Lake Bonneville: Geology and Hydrology of the Weber Delta District, Including Ogden, U tab

GEOLOGICAL SURVEY PROFESSIONAL PAPER 518

Prepared cooperatively by the U.S. Geological Survey and the U.S. Bureau of Reclamation with the cooperation of the Utah State Engineer

Lake Bonneville: Geology and Hydrology of the Weber Delta District, Including Ogden, Utah

By J. H. FETH, D. A. BARKER, L. G. MOORE, R. J. BROWN, and C. E. VEIRS

GEOLOGICAL SURVEY PROFESSIONAL PAPER 518

Prepared cooperattvely by the U.S. Geological Survey and the U.S. Bureau of Reclamation with the cooperation of the Utah State Engineer

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1966 UNITED STATES DEPARTMENT OF THE INTERIOR

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY

William T. Pecora, Director

Library of Congress catalog-card No. 66-260

For sale by the Superintendent of Documents, U. S. Government Printing Office Washington, D. C. 20402 PREFACE

During much of Pleistocene time, and probably earlier, northern Utah was occupied by lakes of large extent. The best known and last widespread lake in this area was Lake Bonne­ ville. At maximum extent, Lake Bonneville was approximately as large as Lake Michigan, about 20,000 square miles, and as much as 1,000 feet deep. The relics of Pleistocene Lake Bonneville are modern Utah Lake, Great Salt Lake, and Sevier Lake. In 1890 the U.S. Geological Survey published G. K. Gilbert's classic study of Lake Bonne­ ville, which is still the only study of the lake that includes its entire basin. In 1946 the Geo­ logical Survey began a restudy of the geology of the Bonneville Basin to evaluate in greater detail the geologic history and the resources of the region (Hunt and others, 1953; Bissell, 1963; Williams, 1963). This report is concerned primarily with the Weber Delta district, an area containing the Weber Delta, the largest delta formed in glacial Lake Bonneville. Today the Weber Delta district is constituted of broad plains and terraces, extending from the shore of Great Salt Lake to the base of the Wasatch Range, and is occupied by one­ sixth of Utah's one million people. The Weber River still carries some sediment to the lake, but its present significance to the economy of the region is as a source of water for irrigation and for municipal and industrial use. The Weber Delta district has a semiarid climate, with average annual precipitation insufficient for crops, and the further handicap that only one-third of the annual total falls during the growing season. The limit of human occupancy of the district is, therefore, set by the extent to which the surface and subsurface water resources can be managed to yield perennial supplies. The characteristic flow pattern of the Weber River and its principal tributaries includes a freshet in the spring from melting snows in the mountains, a rapid diminution to a minimum by late summer, and runoff near this minimum level throughout the winter and until the next freshet. In addition to these seasonal fluctuations there are marked variations from year to year, so that the maximum annual runoff of record may be 5-10 times the minimum. The water of Weber River was first used by new settlers for irrigation in 1848, and rights to all the normal summer flow of the river and its perennial tributaries had been established before 1896. Later, reservoirs were developed for assurance of water supply throughout the irrigation season. Three major reservoirs- Echo, East Canyon, and Pine View- have been in opera­ tion more than a quarter of a century, chiefly to provide irrigation water to the Weber Delta district; but as of 1950, the combined storage capacity of these reservoirs was less than a quarter of the average annual runoff of the Weber and Ogden Rivers. The Weber Basin Project of the U.S. Bureau of Recla~ation, authorized in 1949, provides for comprehensive development of the water of the Weber River drainage basin to yield ulti­ mately an average of 278,000 acre-feet of water annually, of which 166,000 acre-feet is for irrigation of about 133,000 acres of land, 52,000 acre-feet for municipal and industrial use in the Weber Delta district, and 60,000 acre-feet for migratory waterfowl refuges. The project includes enlargement of the Pine View and East Canyon dams and reservoirs and construction of the Wanship and Lost Creek dams, thus increasing the mountain reservoir storage to more than double the capacity prior to 1950. Additional storage will be provided by Willard dam in Willard Bay, formerly an arm of Great Salt Lake. The project also includes construction of wells and drains in the integrated development and management of the basin's water resources. Conjunctive use of subsurface reservoirs with surface reservoirs will be essential to ultimate full development of the water resources, because the total surface storage, even with Willard Reservoir, will still be less than the average annual production of the river system. Thousands of wells are in the Weber Delta district, many of them more than 50 years old, and most of them flowing wells of small diameter and small yield. The total discharge from III IV PREFACE

these wells - about 25,000 acre-feet per year, of which one-third comes from about 60 pumped wells of large capacity- has been small in comparison with the quantities diverted from the Weber and Ogden Rivers; but this water is important in municipal and rural domestic supply, stock watering, industrial supply, and irrigation of small tracts. The wells are distributed widely but irregularly over the district, reflecting in part the conditions of occurrence of usable ground water. An evaluation of the ground-water resources of the Weber Delta district at present would show the occurrence of ground water, not under original conditions, but under conditions modi­ fied by discharge from wells, by application of surface water for irrigation, and by artificial facilities for drainage of land and disposal of water. Further modifications can be expected as additional water of the Weber Basin project is used in the area. Thus, the source, move­ ment, storage, and discharge of ground water will be modified by man's operations; and they can be modified to maximum benefit and minimum detriment to his welfare. But this requires an adequate understanding of the hydrology - a greater understanding than we now have, and one that will require continuing observation and interpretation of the effects of develop­ ment and use of the water throughout the project area. The sediments of the Weber Delta constitute the framework through which ground water moves, and they are thus a controlling factor in the natural storage and circulation and also in the effects of man's activities. The geology of the Weber Delta- texture, sorting, bedding, and structure, which affect the permeability of the sediments; soluble materials which may degrade the water quality; other features which influence the infiltration, percolation, and discharge of ground water - is thus a subject of major and continuing importance in making optimum use of the ground-water resource. CONTENTS

Page Page Preface ______III Water resources ______- __ -- __ ------33 Abstract______1 Water budget ______-- __ --- _--- _--- ______33 Introduction______3 Surface water ______-- ___ -- _--- ___ - ______33 Purpose and scope of the study______3 Water entering the area ______33 Location and definition of the project area______5 Water leaving the area ______34 Previous investigations______5 Ground water ______35 Acknowledgments______6 Occurrence______35 Physical geography______6 Ground-water subdistricts and their aquifers___ 36 Economic geography______7 Weber Delta subdistrict______36 Climate______9 Delta aquifer______36 Well-numbering system used in Utah______9 Sunset aquifer______37 Geology______10 Shallow aquifers______37 Methods of study______11 Ogden-Plain City subdistrict______37 Boundaries of the ground-water basin______11 North Ogden subdistrict______38 Surface geology______12 West Warren subdistrict______38 Stratigraphy and water-bearing properties Little Mountain subdistrict______38 of the rocks______12 Kaysville-Farmington subdistrict______38 Rocks of pre-Quaternary age______12 Recharge ______38 Precambrian rocks______12 Source of recharge ______- __ -- ___ - ______38 Paleozoic rocks______12 Principal recharge area ______38 Other pre-Quaternary rocks______13 Summary of recharge______39 Quaternary deposits______13 Recharge from surface streams______39 Problems in separating and identifying for­ Weber River ______39 mations of the Lake Bonneville Group__ 14 Ogden River ______41 Lake Bonneville Group______16 Mountain-front streams______41 Alpine Formation______16 Mountain-front subsurface recharge______41 Bonneville(?) Formation______19 Evidence from the piezometric surface and Provo Formation______19 from chemical-quality data______41 Recent deposits______19 Evidence from Weber Canyon radon Structure ______20 studies ______- ___ - ___ - - __ - - _ _ 42 Folds ______20 Evidence from Gateway Tunnel______42 Major faults ______..: ______20 Recharge from precipitation, irrigation, and Minor faults______22 canals ______43 Subsurface geologic studies______22 Direct infiltration of precipitation______43 Peg model and drillers' logs______23 Seepage from irrigated areas and canals___ 43 Lithofacies maps______25 Artificial recharge experiments______44 Logs of test wells______2 5 Storage______45 Gravity survey ______26 Volumes of water in the ground-water reser- Shallow-reflection seismic survey______28 voir ______45 Volume of unconsolidated rock ______28 Changes in storage in the Weber Delta Formation boundaries in the subsurface______30 subdistrict______45 Pliocene ______30 Active storage in the Weber Salt Lake Formation ______30 Delta subdistrict______46 Pleistocene(?)______30 Method 1______46 Pleistocene______30 Method 2______47 Lake Bonneville Group______30 Water recoverable by partial dewatering Alpine Formation______30 of the artesian aquifers ______47 Provo Formation ______31 Weber Delta subdistrict______47 Paleontology ______31 Method 1______48 Invertebrate fossils______31 Method 2______48 Vertebrate and plant fossils ______32 Other areas______49 Radioactive age determination______32 Long-term fluctuations in artesian pressure____ 49

v VI CONTENTS

Page Page Water resources- Continued Water resources- Continued Ground water - Continued Chemical quality - Continued Discharge ______----~-----______49 Chemical-quality changes in the subsurface______63 Discharge from wells______49 Natural radioactivity of ground water, by A. B. Discharge by springs______50 Tanner ______63 Aquifer tests______52 Evaporation and evapotranspiration studies______66 Hydraulic characteristics______52 Evaporation______66 We11 interf eren ce ______53 Evapotranspiration______66 11ovement______54 Area 1 - Cultivated crops depending on irrigation_ 68 Direction______54 Areas 2 and 3 - Saltgrass pasture and Volume of water moving through the Weber cattails______68 Delta subdistrict______54 Area 4 - Dry-land crops, grasses, and Leakage into Great Salt Lake______56 shrubs______69 Chemical quality______57 Area 5- No vegetation -salt-crust barrens___ 69 Compilation and analysis of data______57 Area 6- No vegetation- water in drains, canals, and streams______70 Chemical quality of ground water by subdistricts____ 60 Weber Delta subdistrict______60 Area 7- Vegetation diverse- scattered municipal and industrial areas______70 Ogden-Plain City subdistrict______61 Future development ______70 North Ogden subdistrict______62 Utilization of substandard water______70 West Warren subdistrict______62 Development of ground water______71 Little 11ountain subdistrict______62 References ______72 Kaysville-Farmington subdistrict______63 Index ______75

ILLUSTRATIONS

[Plates in pocket)

PLATE 1. Geologic map of the Weber Delta district. 2. Map of the Weber Delta district showing the ratio, in percent, of clay and silt between the land sur- face and a depth of 200 feet. 3. 11ap of the Weber Delta district showing the ratio, in percent, of clay and silt below 200 feet. 4. Generalized logs of four deep test wells in the Weber Delta district. 5. Contour map and profile of top of Delta aquifer. 6. Contour map and profile of top of Sunset aquifer. 7. Hydrograph of discharge from Gateway Tunnel. 8. Hydrographs of selected wells in the Weber Delta district. 9. 11ap of the Weber Delta district showing generalized piezometric surfaces and part of the water table in December 1955. 10. 11ap of the Weber Delta subdistrict showing the line of reference used in calculating the underflow through the subdistrict and the piezometric surface of the Delta aquifer. 11. Diagram showing general chemical character of water in the Weber Delta district. Page FIGURE 1. Index map showing the Weber Delta district and ground-water subdistricts______4 2. 11ap of the Weber Delta district showing average October-April precipitation______8 3. Well-numbering system______10 4. Diagram showing percentages of fine-grained material in the Alpine and Provo Formations and reworked Alpine deposits______16 5. Photograph of cliff-forming clay of the Alpine Formation______17 6. Photograph of multiple fault facets on the west front of the Wasatch Range______21 7. Logs of two test wells on the Weber River flood plain ______24 8. Simple Bouguer anomaly map of the Weber Delta district______27 9. Sections showing approximate bedrock profiles and thickness of the overlying unconsolidated material in the Weber Delta district______29 10. 11ap of ground-water subdistricts in the Weber Delta district showing probable areas of ground- waterrecharge ______40 11. Hydrograph of Bureau of Reclamation test well 1 showing effects of artificial recharge______44 12. 11ap of the Weber Delta district showing selected hydrologic data______51 13. Graph showing relation between permeability and assumed grain size______55 14. 11ap showing chemical character of ground water______59 15. Graph showing progressive cation exchange in ground water at increasing distances from the mouth of Weber Canyon______64 16. 11ap of the Weber Delta district showing areas of vegetation and salt crust______67 CONTENTS VII

TABLES

Page TABLE 1. Mean monthly temperatures and precipitation at Ogden Sugar Factory and Salt Lake City Airport______9 2. Generalized stratigraphic column of the consolidated rocks that crop out in and near the Weber Delta district______12 3. Pebble-count analyses of gravel in the Provo and Alpine Formations of the Lake Bonneville Group ______15 4. Water budget of the Weber Delta district, from an altitude of 5,000 feet to the shoreline of Great Salt Lake in 1952______33 5. Estimated annual runoff from mountain-front streams, T. 3 N. to T. 7. N., inclusive______41 6. Calculation of volumes of water available for recharge by subsurface flow from the mountain front, T. 3 N. toT. 7 N., inclusive ______42 7. Discharge from wells in the Weber Delta district in 1954 ______50 8. Results of aquifer tests in the Weber Delta district______-52 9. Chemical analyses of representative samples of ground and surface water in the Weber Delta district______58 10. Chemical and radiochemical analyses of waters from Utah Hot Springs and Hooper Hot Springs__ 65 11. Comparison of evaporation of water from standard Weather Bureau pans at the Ogden Bay Bird Refuge and the Bear River Bird Refuge, for the period May-October 1955; and May­ October evaporation from 1949 to 1955 at the Bear River Bird Refuge______66 12. Size of areas with different evapotranspiration characteristics in the Weber Delta district______68 13. Annual consumptive use of water by various crops in the Weber Delta district______68 14. Consumptive use of water by saltgrass and cattails grown in tanks at the Ogden Bay Bird Refuge during the 1955 growing season ______69 15. Computation of upward leakage from salt-crust evaporation experiments______70

LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT INCLUDING OGDEN, UTAH

By J. H. FETH, D. A. BARKER, L. G. MOORE R. J. BROWN, and C. E. VEIRS

ABSTRACT sidered closely equivalent to strata mapped as the Bonneville A cooperative investigation to determine the geology of Formation in northern Utah Valley in central Utah. In the the Weber Delta district, with emphasis on the occurrence Weber Delta district, however, no clear disconformity was and chemical quality of ground water, was made by the U.S. found at the base of the sand and gravel units, and there­ Geological Survey and the U.S. Bureau of Reclamation with fore these high-level sand and gravel deposits are called Bon­ the later assistance of the Utah State E~gineer in the final neville ( ?) and Alpine Formations undifferentiated. They preparation of the report. The Weber Delta district covers are characteristically only 20-30 feet thick. Sand and gravel an area of almost 400 square miles between the Wasatch of the Provo Formation, characteristically 10-30 feet thick, Range and the east shore of Great Salt Lake in north-central cover broad areas of the Weber Delta benchland and small Utah. The district, which is about 30 miles long and 3-20 areas of the Ogden Delta; locally, deposits of gravel or sand miles wide, is dominated by the Wasatch Range on the east. of the Provo are less extensive. West of the mountains is a generally narrow foothill area, Sediments of Recent age are at the surface in much of the from which flatlands, interrupted by a few low sand ridges, Weber Delta district. Extensive lacustrine or flood-plain slope gently westward to the shore of Great Salt Lake. deposits are at altitudes between 4,200 and 4,300 feet; the Breaching the foothills and the flatlands near the center of channels of the modern rivers are characterized by variable the district is the Weber Delta, which is the largest of the thicknesses of gravel; patches of gravel extending far west­ deltas built in the Pleistocene Epoch by Lake Bonneville on ward reflect the presence of old channels of the Weber River an open plain. The Weber Delta, the smaller delta of the or other major streams; locally, extensive deposits of col­ Ogden River to the north, and the alluvial fans of several luvium are conspicuous along the Wasatch front; and clay small streams, coalesce to form a belt of plateaulike high­ deposited by Great Salt Lake underlies the western boundary lands from 2 to 7 miles wide and about 10 miles long from of the district. The Wasatch fault, which is part of a fault north to south. Ten miles north of the city of Ogden the zone of great regional extent, is the largest geologic struc­ Pleasant View salient projects westward from the front of ture in the Weber Delta district. It is a· normal fault, the Wasatch Range, and about 15 miles west of the mountain downthrown to the west, and dips on the fault surface front, Little Mountain rises 450 feet above the surface of range from about 20° to as much as 70° to the west. Prob­ the nearly level plain. ably the fault is not a single break but rather a zone of The climate of the Weber Delta district is temperate and movement a mile or more in width. semiarid. The mean annual temperature is about 52°F, and Geophysical evidence suggests that the bedrock surface the annual precipitation ranges from about 12 inches near slopes very steeply just south of the Pleasant View salient, the western part of the district to about 20 inches adjacent as though along a major normal fault. Indirect evidence to the base of the mountains. The precipitation on the suggests that this fault may extend a considerable distance. mountains, in the headwaters of the Weber and Ogden Riv­ Another fault zone east of Little Mountain probably trends ers, however, is as much as 50 inches per year. north-south, paralleling the Wasatch fault. A gravity sur­ The Wasatch Range and Little Mountain consist of con­ vey shows that the bedrock between the Wasatch Range and solidated rocks of Precambrian and Cambrian age. The Little Mountain has the general configuration of an elongate deposits exposed in the rest of the district are unconsolidated trough or somewhat canoe-shaped sink, the deepest part of and weakly consolidated rocks of the Lake Bonneville Group which is about 5 miles west of the Wasatch fault scarp. of Pleistocene age or younger deposits of Recent age. The gravity anomalies imply a maximum thickness of 6,000 The Lake Bonneville Group in the Weber Delta district to possibly 9,000 feet of unconsolidated rock in the trough. consists of the Alpine, Bonneville ( ?) , and Provo Formations. The valley fill is an intricately interfingering mass of len­ Sand and gravel of the Alpine Formation are exposed prin­ ticular or wedge-shaped strata of gravel, sand, silt, and cipally in areas very close to the mountain front, but the clay. Strata deeper than about 1,000 feet below the land most distinctive lithology of the Alpine in the district is a surface have been explored by only a few wells. Profiles cliff-forming slabby clay that has a thickness of at least prepared from subsurface data permitted tentative correla­ 80 feet. Deposits of sand and gravel at altitudes ranging tions of a few fairly continuous north-trending zones; the from 5,100 to more than 5,200 feet above sea level are con- writers infer that many of the beds were deposited by lake 1 2 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT currents paralleling the shoreline of Lake Bonneville. The have small yields, but the water is of good chemical quality. valley fill forms the ground-water reservoir, and local li­ Westward from the mountains the sodium bicarbonate con­ thology has a marked influence on the quantity and quality tent of the water increases by ion exchange, and the water of water yielded by wells. becomes less suitable for irrigation. A water budget shows that about 950,000 acre-feet of wa­ The original source of all water that recharges the ground­ ter enters and leaves the Weber Delta district annually. The water reservoir in the Weber Delta district is precipitation larger sources of inflow are the Ogden and Weber Rivers that falls on the drainage basin. The estimated recharge which, respectively, contribute 160,000 and 360,000 acre-feet to the aquifers of the district is about 70,000 acre-feet per of water annually, and precipitation on areas below 5,000 yea1·, and the principal recharge area consists of the channel feet which contributes an estimated 350,000 acre-feet of of the Weber River and a belt of sand and gravel ranging water annually. About 330,000 acre-feet of water leaves the in width from a few to a few thousand feet just west of the district annually in the Weber River; about 80,000 acre-feet mountain front. The direct sources of recharge are the leaves the district annually in other surface channels; and Weber and Ogden Rivers, mountain-front streams, infiltra­ about 520,000 acre-feet leaves the district annually by evap­ tion of precipitation, irrigation seepage, canal losses, and otranspiration. Unaccounted for is about 20,000 acre-feet, subsurface flow from the mountain front. The latter, which may be direct leakage into Great Salt Lake. amounting to about 30,000 acre-feet per year, is the largest The Weber Delta district has been divided into the Weber source of recharge. Artificial-recharge experiments, during Delta, Ogden-Plain City, North Ogden, West Warren, Little which about 2,170 acre-feet of water infiltrated through a Mountain, and Kaysville-Farmington subdistricts. The 3 14-acre gravel pit during a 7-week period, indicated that boundaries of the subdistricts are based principally on the artificial recharge on a large scale may be feasible. quality of the water yielded by the aquifers in the The total quantity of water in storage in the 200 cubic subdistricts. miles of unconsolidated sediments that underlie the Weber The Weber Delta subdistrict has a greater present and Delta district (not including the Kaysville-Farmington sub­ potential development of ground water than any of the other district and the northwestern part of the Ogden-Plain City subdistricts. The Delta and Sunset artesian aquifers yield subdistrict), assuming an average porosity of about 25 per­ most of the ground water in the subdistrict. The Delta aqui­ cent, is estimated to be almost 170 million acre-feet. How­ fer, which is probably 50-150 feet thick and whose top is ever, much of this water is of poor chemical quality or is 500-700 feet below the land surface, is highly permeable and in fine-grained sediments, which do not yield water readily supplies water to many of the pumped wells of large yield. to wells. The maximum known depth of fresh water is 1,300 The Sunset aquifer, which is probably 50-250 feet thick and feet below the land surface. The quantity of water that whose top is generally 250-400 feet below the land surface, could be withdrawn in the Weber Delta subdistrict by lower­ is less permeable and yields smaller quantities of water to ing water levels a maximum of 150 feet, but still not wells. The water from both aquifers is of good chemical dewatering the artesian aquifers, was calculated by 2 meth­ quality, although hard. In areas near Roy and Syracuse, ods to be 80,000 or 100,000 acre-feet. The additional quan­ shallow artesian aquifers 50-150 feet below the land surface tity of water that could be withdrawn in the subdistrict by yield water that is more mineralized than the water from dewatering the upper 50 feet of the artesian aquifer was the underlying Delta and Sunset aquifers; whereas in an calculated by 2 methods to be 300,000 or 600,000 acre-feet. area near Layton, water from wells is less mineralized than The amount of water that could be withdrawn from the re­ water from the Delta and Sunset aquifers. mainder of the Weber Delta district by dewatering the upper The Ogden-Plain City subdistrict is underlain by pre­ 50 feet of the artesian aquifers was calculated to be about dominantly fine-grained materials, but large yields can be 700,000 acre-feet. Long-term trends of water levels, from obtained from wells in parts of the subdistrict. The chemical records that go back as far as 1935, indicate that the prin­ quality of water varies both laterally and vertically, but cipal effects of pumping are local and that there has been because of a high dissolved-solids and sodium content, the little change in storage from 1935 to 1961. water is commonly unsuitable for irrigation. Ground water in the aquifers of the Weber Delta district Wells obtain relatively small yields from· the artesian aq­ in general moves westward from the Wasatch Range toward uifer in the North Ogden subdistrict, but the water rises to Great Salt Lake. Calculations based on the hydraulic gra­ the highest altitude known in the Weber Delta district. Re­ dient and the permeability of materials in the Weber Delta charge is from the mountain front. The water is of excel­ subdistrict between the surface and 1,300 feet indicate that lent chemical quality, and it can be used for most purposes about 40,000 acre-feet of water flows through the district without treatment. annually. Some of this water is discharged by wells, but The West Warren and Little Mountain subdistricts are about 20,000 acre-feet may continue westward to discharge underlain predominantly by the fine-grained materials and into the lake. yields of wells are small. The water in the West Warren The discharge of ground water from pumped and flowing subdistrict is suitable for domestic use; but because it has a wells in the Weber Delta district in 1954 was about 25,000 high sodium bicarbonate content, it cannot be used readily acre-feet. Discharge from springs during the same period for irrigation. Water in the Little Mountain subdistrict probably was on the order of a few thousand acre-feet. contains considerable sodium chloride and is unsatisfactory Twenty aquifer tests were made in the Weber Delta dis­ for most uses. trict, principally using the larger pumped wells that tap Aquifers of the Kaysville-Farmington subdistrict are sep­ the Delta aquifer. Coefficients of transmissibility obtained arated from the aquifers of the Weber Delta subdistrict to from these tests range from 2,000 to 300,000 gallons per day the north by a bedrock high. Wells in the Kaysville­ per foot for the entire district and from 25,000 to 190,000 Farmington subdistrict near the Wasatch Range generally gallons per day per foot for the Delta aquifer. The co- INTRODUCTION 3 efficient of storage for the Delta aquifer as determined from tesian pressures, changes in discharge, and changes in chem­ 3 tests averaged 7.9X10-4 • The tests in the Weber Delta ical quality. subdistrict indicate that the aquifers to depths of about 700 INTRODUCTION feet have relatively large coefficients of transmissibility. PURPOSE AND SCOPE OF THE STUDY The few tests made in other subdistricts indicate that the aquifers in the North Ogden subdistrict have a much lower As a part of the Weber Basin Project, the U.S. coefficient of transmissibility; the aquifers in the Ogden­ Bureau of Reclamation sponsored a comprehensive Plain City subdistrict have a relatively large average co­ study of the ground-water resources of a 400- efficient of transmissibility; and the aquifers in the square-mile area that includes the Weber Delta and Kaysville-Farmington subdistrict have a considerable range in transmissibility. some adjacent lands. The study was made from The chemical quality of ground and surface water in the February 1953 to July 1956, prior to the completion Weber Delta district is known from analyses of more than of any of the major elements of the Weber Basin 500 samples. The distribution of the main chemical types Project. The Utah State Engineer contributed to of ground water and mixtures of chemical types is shown the final preparation of the report as part of the on a map of the district. The district contains three main regular State cooperative program with the U.S. chemical types of ground water-calcium magnesium bicar­ bonate, sodium chloride, and sodium bicarbonate. The first Geological Survey. two types are considered to be original types, whereas the Preparation of the report was the overall respon­ sodium bicarbonate type was probably derived by the action sibility of J. H. Feth, U.S. Geological Survey. Ex­ of ion exchange on the calcium magnesium bicarbonate type tensive and critical contributions. to various sections water. The sodium concentration tends to increase from the were made by the other authors, all of the U.S. mountains westward toward the Great Salt Lake. Bureau of Reclamation, as follows: (1) Ground wa­ The water of Utah Hot Springs and Hooper Hot Springs has a high content of radioactive constituents. Analyses of ter, D. A. Barker and L. G. Moore, (2) chemical water from wells and springs in the vicinity of the Pleasant quality, C. E. Veirs and D. A. Barker, and (3) View salient showed a small increase in the average radon evaporation and evapotranspiration, R. J. Brown. concentration of water from wells near the southern margin Individual contributions of others are recognized in of the salient and in the vicinity of projections of fault the acknowledgments. traces into the area covered by unconsolidated sediments. The comprehensive investigation was undertaken This suggests that the radon is derived from water rising along faults. The increase of radon, however, could also re­ to determine ( 1) the geology of the area with em­ sult from the precipitation of radium at favorable sites gov­ phasis on the occurrence of ground water; (2) the erned by changes in permeability of the aquifers, rather recharge, use, and discharge of ground water; (3) than from highly radioactive waters rising along faults. the chemical quality of ground water; and ( 4) the Studies of evaporation and evapotranspiration in 1954 amount of ground water available for development. and 1955 indicate that about 520,000 acre-feet of water is Various methods of investigation were used: ( 1) discharged annually from the nearly 400 square miles in the district between the 5,000-foot level and the 1952 shoreline mapping surface geology, especially unconsolidated of Great Salt Lake. rocks, and studying subsurface geology using The district was divided into seven areas based on the drillers' logs, well cuttings, and geophysical data; principal type of vegetation in each area. The areas, the (2) defining the recharge areas; (3) studying the principal type of vegetation in each area, the acreage of each hydrologic properties of the aquifers ; ( 4) making area, and the amount of water in acre-feet evaporated or an inventory of flowing wells and large-yield transpired annually in each area are as follows: Area 1, cultivated crops depending on irrigation, 7 4,000, and 170,000; pumped wells; (5) investigating springs, and sur­ area 2, saltgrass pasture, 54,600 and 162,000; area 3, cat­ face drains that carry water out of the area; (6) tails, rushes, and reeds, 11,500 and 59,000; area 4, dry-land studying evaporation and transpiration; and (7) crops, grasses, and shrubs that depend on precipitation, determining the chemical quality of ground and 32,800, and 45,000; area 5, no vegetation (salt-crust bar­ surface water. rens), 60,000, and 40,000; area 6, no vegetation (open fresh The investigation was concerned almost entirely water in drains, canals, and streams), 5,800 and 24,000; area 7, vegetation diverse (scattered municipal and indus­ with an area underlain by unconsolidated material. trial areas), 16,499, and 22,000. Consolidated rocks, such as those composing the Future development of the water resources of the Weber adjacent Wasatch Range, were studied only where Delta district will include increased use of surface water; such data were needed to understand the ground­ may include the beneficiation of presently unused water, such water conditions. as sewage, industrial waste, and saline water; and should This report discusses the status of ground­ include the use of the ground-water body as a reservoir. Withdrawal of ground water should be increased to lower water occurrence at the time of the investigation. the artesian pressure and reduce wastage, and continuing Certainly this status will change as development studies should be made of changes in water levels and ar- proceeds and water use by the Weber Basin Project 4 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

R. 3 W. R. 2 W. R. 1 W. R. 1 E.

BOX ELDER CO / ------______// / WEBER CO 7 N. / NORTH OGDEN / SUBDISTRICT / Plain City D 0 North Ogden

T. 6 N.

WEBER (:::y

T. 5 N. WEBER CO \ - DA VISCO- ·...... - DELTA Sun,et\.. West Point

Clearfielc? ·•.

Syracuse 0

SUBDISTRICT T. 4 N.

EXPLANATION Layton 0

Approximate outline of Weber Delta

Subdistrict boundary

T. 3 N. Farmington 0

0 2 4 5 MILES •

FIGURE 1.-Index map showing the Weber Delta district, Utah, and ground-water subdistricts. INTRODUCTION 5 increases as expected ; this report, therefore, will Delta district thus includes the area in Tps. 3-7 N. be of value in defining the conditions prior to proj­ that is between Great Salt Lake and the Wasatch ect operations. front. The features that are related to the geology of The Weber Delta district has been divided into the Weber Delta district-the recharge areas of six subdistricts. The Weber Delta subdistrict is the ground-water reservoir and the thickness, the largest part of the Weber Delta district and depth, and areal extent of the aquifers, for in­ the part in which ground water has been most de­ stance-are permanent and subject to negligible veloped. The boundaries of the Weber Delta sub­ change. But our information concerning them is district and of the other five subdistricts-North incomplete, and conclusions drawn now may re­ Ogden, Ogden-Plain City, West Warren, Little quire considerable revision as more data become Mountain, and Kaysville-Farmington-are shown available. Thus, the present evaluations of various at small scale in figure 1 and at a larger scale in aspects of the ground-water resources might best figure 10. be classified as working hypotheses-to be ac­ PREVIOUS INVESTIGATIONS cepted until more information is available. Great Salt Lake and its basin are mentioned in the accounts of various trappers and explorers LOCATION AND DEFINITION OF THE PROJECT AREA who visited the area during the period 1800-70. The Weber Delta is the largest delta built into Brief discussions of the geography and geology of Lake Bonneville on an open plain (Gilbert, 1890, the area appear in reports of the U.S. Geographic p. 164) and consists of material brought in by the and Geologic Surveys published during the 1870's. Weber River. This delta and adjacent areas, com­ In 1890 the U.S. Geological Survey published Mono­ prising a total area of almost 400 square miles, graph 1, by G. K. Gilbert, entitled "Lake Bonne­ constitute the Weber Delta district (fig. 1). The ville," which included the first comprehensive district is between the west face of the Wasatch survey of the geology of the surficial deposits of the Range and the east shore of Great Salt Lake and Great Salt Lake Basin. Gilbert set up a chronol­ is 30 miles long from north to south and from 3 to ogy of Lake Bonneville and described in consider­ 20 miles wide. The Weber Delta district was able detail the lake-formed features in the basin. named after the Weber Delta of Gilbert by Thomas Gilbert's work has furnished the framework on and Nelson, who included the district in a larger which all subsequent investigations of the basin hydrologic unit which they identified as the East have been based, at least in part. Gilbert (1928) Shore area. According to Thomas and Nelson presented his conclusions regarding Basin-Range ( 1948, p. 63): structures, based largely on his work along the The East Shore ground-water area is bordered on the west front of the Wasatch Range. north by the Lower Bear River Valley and on the south by The geology of the Wasatch Range has been the City Creek spur of the Wasatch Range, beyond which studied by various investigators, notably by A. J. lies the Jordan Valley, in which Salt Lake City is situated. Eardley who published several papers culminating The East Shore area is a well-defined ground-water unit in 1944 in an overall discussion of the north-central * * * For the purpose of describing the ground-water condi­ Wasatch Range (Eardley, 1944). A summary of tions, the East Shore area may conveniently be divided into the geologic environment of the East Shore area is three districts: the Bountiful district in Davis County, in­ included in a statement by Blackwelder (1948) on cluding that part of the East Shore area lying south of the important geologic features of the Great Basin. Farmington Bay; the Weber Delta in Davis, Weber, and Box Ground-water conditions in the vicinity of Ogden Elder Counties, extending from Farmington Bay to Bear River Bay of Great Salt Lake; and the Brigham district of were studied by Dennis and McDonald (1944), and Box Elder County, extending north from Bear River Bay to additional work in this area was done by Dennis the lower Bear River Valley. and Nelson ( 1945). Dennis ( 1952) studied re­ Thomas and Nelson indirectly defined the south­ charge in the East Shore area. ern boundary of the Weber Delta district when Work done in adjacent and comparable areas they set the northern boundary of the Bountiful provided information that was useful during this district "at the north edge of Township 2 North, study. Thomas and Nelson (1948) described the Salt Lake Base and Meridian" ( 1948, p. 64). They geology and occurrence of ground water in the did not precisely define the northern boundary of Bountiful district of the East Shore area. The the Weber Delta district ; therefore, in this report sediments of Pleistocene Lake Bonneville in areas it is set as the north edge of T. 7 N. The Weber near Salt Lake City were described briefly by Jones 6 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT and Marsell (1952). The geology of northern Utah The Utah State Engineer made available logs of Valley was discussed by Hunt, Varnes, and Thomas more than 2,000 water wells and provided addi­ (1953) and by Bissell (1952). Ground water in tional information and assistance. H. D. Goode and part of the East Shore area was studied by W. K. J. S. Gates assisted in preparing the report for Hamblin (written commun. 1954), and Williams publication. (1952) described the geology of Cache Valley, Members of the geology departments of Utah's Utah, and the ancient outlet of Lake Bonneville at universities shared their knowledge of local geo­ Red Rock Pass, Idaho. The relation of fossil soils logic features and discussed problems associated to Lake Bonneville was considered by Hunt and with the deposits of Lake Bonneville. Valuable Sokoloff (1950) and Gvosdetsky and Hawkes assistance was received from Professors A. J. (1953). A study of evaporation from Great Salt Eardley, W. L. Stokes, R. E. Marsell, and D. J. Lake and the influence of ground water inflow in Jones, of the University of Utah; J. Stewart Wil­ maintaining the lake level was prepared by Peck liams, of Utah State University; and H. J. Bissell, (1954). Eardley (1955) edited a guidebook deal­ of Brigham Young University. Dr. Jones was espe­ ing with Tertiary and Quaternary geology of the cially helpful in sharing his knowledge of ostracode eastern Bonneville Basin. faunas. Thanks are due to the many residents of the ACKNOWLEDGMENTS East Shore area who gave permission to install The study was preceded by about 3 months of water-stage recorders on privately owned wells or geologic mapping during the summer of 1951 by to make periodic measurements of water levels. P. E. Dennis, of the U.S. Geological Survey. Valu­ Appreciation is also expressed to the municipal able assistance and suggestions were obtained from officials and personnel of Federal installations who many individuals during this study. A. S. Rogers, have contributed useful information and cooperated of the Geological Survey, made a study of radon in other respects. Well drillers were generous in content in waters from part of the area, and providing information, and in several instances D. R. Mabey, also of the Geological Survey, pre­ they collected drill cuttings for examination. pared a preliminary gravity-contour map showing the configuration of the bedrock surface of the PHYSICAL GEOGRAPHY area. Fossil assemblages were identified and their The eastern boundary of the Weber Delta dis­ ecologic significance discussed by I. G. Sohn, D. W. trict is the western front of the Wasatch Range, Taylor, G. E. Lewis, and M. J. Hough, of the Geo­ whose peaks rise 4,000-5,000 feet above the plain logical Survey; by C. B. Schultz, T. M. Stout, and east of the Great Salt Lake. The Wasatch front L. G. Tanner, of the Upper Cenozoic Research is a topographic expression of the Wasatch fault Group; by J. P. E. Morrison, of the Smithsonian zone, a geologic feature of regional magnitude that Institute; and by E. J. Roscoe, of the University reflects its structural origin by its linearity and of Utah. the steepness of its slopes. V. D. Jensen, P. S. Moore, and G. M. Ross, engi­ The Weber Delta district consists of two topo­ neers, U.S. Bureau of Reclamation, each worked full graphic units. The eastern unit is a foothill area time on the study during various periods; Moore of varied topography developed on Lake Bonneville assisted in mapping and all participated in the deposits. Locally, the lake deposits form a hill­ hydrologic studies. A. G. Hyde, Regional Labora­ and-valley topography whose linear elements are tory, Bureau of Reclamation, assisted in the chem­ at right angles to the mountain front. This type ical analysis of water samples and in the assembly of topography is found where closely spaced moun­ and interpretation of chemical data. Personnel of tain-front streams have dissected the lake deposits. the U. S. Weather Bureau in Salt Lake City were Elsewhere, the lake deposits form broad terraces, cooperative in furnishing information and equip­ virtually coextensive with the tops of ancient ment and in the discussion of problems, especially deltas, such as the Weber Delta. In some areas those related to evaporation. A precipitation map the foothill zone consists principally of two or three (fig. 2) was prepared especially for this study by fairly broad terraces, the widest of which is at an the Weather Bureau. Noland Nelson, Refuge Man­ altitude of 4,800 feet. In other areas the various ager, Utah State Fish and Game Commission, pro­ levels of Lake Bonneville formed many terraces, vided a site for a weather station at the Ogden so that in profile, looking northward parallel to the Bay Bird Refuge and serviced the station daily. mountain front, the terraces resemble a flight of INTRODUCTION 7 giant steps, with some steps wider and (or) higher more ancient and more lofty delta, but is probably than others. a dune accumulated during the Provo epoch." Gil­ The western and largest topographic unit of the bert's assumption that the hill is an older higher Weber Delta district is a plain of little surface re­ delta is probably correct. Excavation of a similar lief. This plain probably was formed partly by hill north of the river during a phase of the Weber deposition on the floor of Lake Bonneville during Basin Project showed a remarkable sequence of the waning stages of the lake and partly by deposi­ superposed ripple marks, which are probably the tion by the Weber River as it meandered over the result of long-continuing deposition by southward­ plain. The plain ranges in width from 2 or 3 miles moving bottom currents in the ancient lake. near Farmington to about 14 miles north of Ogden. Although dune building has obviously been effec­ Most of the farmland of the region is on the plain. tive in helping to cause the digitate shape of the North of Ogden, where the plain is widest, its higher hills and ridges on the delta, it appears to western limit is marked by Little Mountain, a ridge have been a secondary agent. of bedrock that projects a few hundred feet above In some parts of the Weber Delta district, the the surface of the lowlands and is about 3 miles higher shorelines of Lake Bonneville remain as long, north to south, and as much as 1 mile wide. wave-cut notches on the front of the Wasatch Over most of the area studied, the historic Range. In other places, however, these markings shoreline of Great Salt Lake is marked by a scarp­ are not now visible, either because they were not let ranging from less than a foot to perhaps as well formed or because erosion and mass wasting much as 5 feet in height. This historic high-water has obscured them. North of Ogden and to the mark, at an altitude of about 4,200-4,210 feet, has north of the distri~t the shorelines can be recog­ been taken as the western margin of the project nized only in scattered localities, because they prob­ area. ably have been largely obliterated by mass wastage. The Pleasant View salient interrupts the nearly North of Ogden damaging mudflows have emerged linear Wasatch front about 10 miles north of Ogden from some of the canyons in historic time, and at (fig. 10). The salient is an outcrop of consolidated many places the mountain front has great heaps rock that rises about 1,000 feet higher than the of talus at its base from the rapid breakdown of adjacent plain to the north and south and extends the clifflike face of the range. about 4 miles west of the range front to the south and about 1 mile beyond the range front to the ECONOMIC GEOGRAPHY north. This salient is one of a number of similar The Weber Delta district and adjacent areas structural elements that project from the Wasatch along the western front of the Wasatch Range front along its entire length, but the only one of southward as far as Provo are the most densely prominence within the Weber Delta district. populated parts of the State. According to the 1960 The lake-built features of the Weber Delta dis­ census, the population of Utah was about 900,000; trict and adjacent areas differ from those of other that of Ogden, Salt Lake City, and Provo totaled areas in the Bonneville Basin in that they do not about 300,000, of which the population of Ogden include any of the massive spits and bars described comprised 70,000. Industrial activity in the State by Gilbert (1890, p. 90-170). In his discussion of largely centers in the area extending from Ogden shore features, embankments, bars, spits, terraces, to Provo, and many military installations con­ and deltas, Gilbert (p. 163-164) discussed the area structed in the project area during World War II of the Weber Delta district only in connection with are still active and increase the business activity the deltas of the Ogden and Weber Rivers. He and population of the region. commented that the delta of the Ogden River "is The Weber Delta district has a large farm popu­ exceptional to the general rule in that it is some­ lation that produces beef, dairy products, and what below the Provo horizon," and stated, refer­ domestic fowl. Since the earliest days of trans­ ring to the Weber Delta, that "It is the largest of continental railways, Ogden has been an important all the deltas of the ancient lake built upon an open railroad center. The district also supports a flour­ plain, but, owing to the lightness of its material, ishing food-processing industry which includes flour the details of its form are imperfectly preserved. mills, packing houses, and especially plants where * * * The principal terrace is at the Provo level, fruit and truck-garden produce are canned or and upon this there stands a hill more than 200 frozen. feet high, which may possibly be the remnant of a Clay deposited by Lake Bonneville furnishes raw 8 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

R 3 W. R. 2 W. R. 1 W. R. 1 E.

/--- T. 7 N. / / I D North Ogden

Lit~le Mountain

~::-, -,.~~.\\ 1.::: T. 6 N.

~Sugar Fal'toryt::,

Riverdale

T. 5 N.

Sunset 0

West Point Clearfield 0

0 Syracuse

T. 4 N.

EXPLANATION ------32------Isoh~'Pt Shou'8 average October-April precipi­ totion inten·u1: I inches in the muun­ tuins,;! in1'!1es in the lo1ulands

!':, Weather substation T. 3 N Farmington 0

Adapted from an unpublished 0 4 5 MILES U.S. Weather Bureau map, 1955

FIGURE 2.-Map of the Weber Delta district showing average October-April precipitatiOn durmg the period 1915-55. INTRODUCTION 9 materials for a brick and tile industry that is ade­ Sugar Factory and at Salt Lake City Airport, quate to supply local needs, and the coarser de­ which is about 12 miles south of the Weber Delta posits of the lake provide sand and gravel for an district, is given in table 1. Data from Riverdale active construction industry. Furthermore, the Power House and Farmington were used to adjust farmland itself largely was formed from sand, silt, the long-term normals to the period for which the and clay deposited in Lake Bonneville. Unconsoli­ water budget of the district was calculated. Data dated lacustrine and fluvial deposits form the from Ogden Bay Bird Refuge were used in the aquifers and confining layers in the artesian system studies of evapotranspiration. that furnishes much of the water supply for the region. Many homes below an altitude of 4,300 TABLE 1.-Mean monthly temperatures and precipitation at Ogden feet-the approximate upper limit of artesian flow Sugar Factory and Salt Lake City Airport -have small-diameter flowing wells in their yards [Data from U.S". Weather Bureau] from which water is obtained for domestic use. Mean Temperature Mean Precipitation The nature and behavior of the artesian basin are Ogden Sugar I Salt Lake Ogden Sugar Salt Lake Month Factory, 1929 Airport, 1928 Factory, 1925 Airport, 1928 to 1955 to 1955 to 1955 to 1955 subjects which are discussed extensively in this (oF) I (oF) (inches) (inches) ----- report. January ______25.2 26.5 1.64 1.20 CLIMATE February ______32.1 33.4 1.68 1.23 The climate of the Weber Delta district is tem­ ~arch ______40.3 41.1 1.79 1.66 perate and semiarid. The mean annual tempera­ ApriL ______50.0 50.1 2.23 1. 76 ~ay ______58.4 58.9 1.74 1.56 ture is about 52°F, with recorded extremes of June ______66.2 67.1 1.31 .91 24° below zero and 106° above zero. Temperatures July ______75.6 76.6 .60 .61 below zero are common during a cold winter, al­ August______' 73.2 74.4 .75 .97 though periods of severely low temperatures are Septenaber ______63.2 64.2 1.17 .74 1. 75 1.34 not prolonged because the mountains ward off most October ______52.3 52.9 ~ovenaber ______38.8 39.3 1.67 1.42 of the intensely cold air masses that move out of Decenaber _____ --I 30.1 31.5 1.83 1.34

Canada into the United States. The frost-free AnnuaL __ I 50.5 51.3 18.16 14.74 growing season ordinarily includes the 5 months from May through September. Winds are usually light to moderate, normally WELL-NUMBERING SYSTEM USED IN UTAH ranging from 7 to 10 miles per hour, although The well numbers used in this report indicate the strong damaging winds occur occasionally. Near well location by land subdivision according to a the mountains, air warmed by compression blows numbering system that was devised cooperatively from the canyons and helps to prevent late-spring by the Utah State Engineer and the U.S. Geologi­ frosts. The percentage of hours of sunshine dur­ cal Survey about 1935. The system is illustrated ing the day ranges from 65 to 80, and the relative in figure 3. The complete well number comprises humidity is low, commonly dropping below 30 per­ letters and numbers that designate consecutively cent during midsummer days. The windiness, high the quadrant and township (shown together in percentage of hours of sunshine, high temperatures, parentheses by a capital letter designating the and low atmospheric humidities in the summer quadrant in relation to the base point of the Salt tend to promote high rates of evaporation from Lake base and meridian, and numbers designating water and moist land surfaces and high rates of the township and range); the number of the sec­ transpiration from plants. tion; the quarter section (designated by a letter); Precipitation in the western part of the Weber the quarter of the quarter section ; the quarter of Delta district averages about 12 inches annually the quarter-quarter section; and, finally, the par­ and increases to the east, averaging about 20 inches ticular well within the 10-acre tract (designated by per year near the base of the Wasatch Range. a number). By this system the letters A, B, C, Precipitation in the area as a whole averages about and D designate, respectively, the northeast, north­ 16 inches annually. Most of this precipitation falls west, southwest, and southeast quadrants of the during the October-April period (fig. 2), so that standard base and meridian system of the Bureau irrigation is required to produce most crops. of Land Management, and the letters a, b, c, and Data from several weather substations (fig. 2) d designate the northeast, northwest, southwest, were used during the study. A summary of mean and southeast quarters of the section, of the quar­ monthly temperatures and precipitation at Ogden ter section, and of the quarter-quarter section. 10 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

I I I b 1 a b 1 a I r--b-l--a-- c 1 d c I d I r-- +--- b -1-r---a-- 1 b I ajblaI --c- --d-- I c I d c I d I I I I 6 5 4 3 2 1 ~ I I 7 8 9 10 11 12 ~ :::; I 18 17 16 15 14 13 0 I 0:: T. 2 N. r--- c - - -~-d-- 19 20 21 22 23 24 w 30 29 28 27 26 25 ~ I --~-~ I X I 31 32 33 34 35 36 l I.& w Sec. 12 ~ <( _j X Well (B-2-2) 12dcd-1 .& Well (B-2-2) 12dcd-2 T. 1 1\J. f- _j <( (f) SALT LAKE BASE LINE R. 2 W. R.1 W.

8 A

SALT LAKE BASE LINELB ~

z l?~ :::; Area of Uinta 0 special base 0:: w and meridian ~ c w D ~ <( _j f- _j <( (f)

FIGURE 3.-Well-numbering system used in Utah.

Thus, the number (B-2-2) 12dcd-2 designates well Delta district. The ground-water reservoir con­ 2 in the SE14SW14SEV., sec. 12, T. 2 N., R. 2 W., sists of unconsolidated to poorly consolidated the letter B showing that the township is north of sediments that have been deposited in a large struc­ the Salt Lake base line and the range is west of the turally-controlled basin of consolidated rocks. The Salt Lake meridian; and the number (D-3-2)34 maximum thickness of the unconsolidated rocks is bca-1 designates well 1 in the NE14SW14NWV., perhaps as much as 9,000 feet. The consolidated sec. 34, T. 3 S., R. 2 E., in the southeast quadrant rocks form the eastern, western, and lower boun­ of the standard base and meridian system. daries of the ground-water basin. The unconsoli­ dated sediments in the basin contain the ground GEOLOGY water presently developed and available for devel­ Geology is the major factor controlling the occur­ opment, and they include many strata of low per­ rence and movement of ground water in the Weber meability that confine water in more permeable GEOLOGY 11 beds, causing artesian conditions in much of the tentative because no definitive criteria are available area. by which to identify the formations of the Lake The lithology of the various deposits largely Bonneville Group. determines the areas of recharge and of natural The subsurface geology of the area was studied discharge of ground water. Lithology also deter­ from hundreds of drillers' logs and available mines the yield of the aquifers and the depth to drill cuttings and by constructing a three-dimen­ which development of ground water is presently sional model of the subsurface based on data from feasible, and it is an important determinant of the 300 of the deeper wells for which complete and chemical quality of water in the district. accurate logs were available. Data from two geophysical studies made in the METHODS OF STUDY area during the project were used in making sub­ The rocks in the Weber Delta district were surface interpretations. The U.S. Bureau of Rec­ divided into three principal groups-consolidated lamation, assisted by the Geophysics Branch of the rocks of pre-Tertiary age, unconsolidated and U.S. Geological Survey, made a series of shallow­ poorly consolidated rocks of Tertiary age that com­ reflection seismic profiles in the area; D. R. Mabey, prise part of the basin fill but do not crop out in of the Geological Survey, made a generalized grav­ the district, and the deposits of the Lake Bonne­ ity survey of most of the area. Results of these ville Group of Pleistocene age and younger deposits. surveys are presented in the section titled "Subsur­ Eardley (1944) and Eardley and Hatch (1940) face geologic studies." have reported on the pre-Tertiary rocks. In the present investigation, these rocks were mapped on BOUNDARIES OF THE GROUND-WATER BASIN the Pleasant View salient and on Little Mountain, The northern and southern boundaries of the but they were only examined where they form the Weber Delta district have been previously defined. eastern boundary of the ground-water basin. The consolidated rocks of the Wasatch Range form Mapping of the Lake Bonneville Group in the the eastern boundary of the ground-water basin, Weber Delta district was started by P. E. Dennis, but the eastern boundary of the area that supplies of the U.S. Geological Survey, during a 3-month water that can recharge the ground-water reservoir reconnaissance of the area in 1951. All exposures of the Weber Delta district is at the drainage divide of the Lake Bonneville Group in the district were of the Wasatch Range. In fact, the eastern edge of mapped on airphotos during the period 1953-56. the area supplying water for recharge could be Soil-survey maps were used to supplement direct considered to be the eastern edge of the Weber observations of lithology and mapping of formation River basin in the Unita Mountains, as the Weber contacts. These maps were available for most River is a source of recharge. areas in which strata of the Lake Bonneville Group The western boundary of the Weber Delta dis­ crop out and all areas in which younger sediments trict is the historic high shoreline of Great Salt crop out. The soil surveys were based on data Lake, about 4,200-4,210 feet above mean sea level. from hand-auger holes of various depths, commonly The basin fill, however, extends west of the shore­ at least 5 feet deep. These auger holes were in line, and water in the aquifers underlying the dis­ concentrations ranging from one to many dozens trict moves westward past the line. The western per square mile. During this investigation, hand boundary of the ground-water basin also could be augering was done in areas which had not been considered to be at the western edge of the trough included in earlier surveys, or in which the soil­ of basin fill where a hard-rock ridge extends survey information appeared to be inadequate. along a north-south line that includes the exposures The geologic map, therefore, shows materials that of consolidated rock at Little Mountain in T. 6 N., are exposed at the surface and that extend to Rs. 3 and 4 W. depths of about 5 feet. The floor of the basin, which is formed by con­ Horizontal contacts between lithotypes in the solidated rock, has somewhat the configuration of a unconsolidated rocks are seldom sharp; sand, for canoe having its keel oriented north-south and ris­ example, commonly grades into silt on one side and ing toward the surface near the Pleasant View interfingers with gravel in another direction. The salient on the north and near Farmington on the contacts shown on the geologic map (pl. 1) are, south. The thickness of fill in the trough has not therefore, gradational, and not so sharp as they been fully explored by drilling. Geophysical data appear on the map. The stratigraphic sequence is suggest that the thickness reaches a maximum of 12 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

6,000-9,000 feet over the "keel" of the trough and TABLE.-Generalized stratigraphic column of the consolidated rocks that it ranges elsewhere from a featheredge ad­ that crop out in and near the lVeber Delta district-Continued jacent to the mountains to about 2,500 feet over the Local disconformity. bedrock ridges that are thought to enclose the basin 4. Phyllites, tillites, and quartzites of late Precambrian Feet age: at the north, south, and west. Upper 7,000 ft is dominantly purplish or As defined in this report, then, the ground-water rusty-weathering quartzites; lower 3,000 ft basin of the Weber Delta district is a trough about is arkosites, phyllites, and tillites interbedded 25 miles long, north to south, and as much as 15 with quartzites. The lower part of the miles wide north of Ogden. section is exposed on Little Mountain, but not in the Wasatch front except locally in overthrust plates______10,000 + SURFACE GEOLOGY Angular unconformity. Consolidated rocks of pre-Tertiary age are ex­ 5. Farmington Canyon Complex of Eardley (1944) posed in the Wasatch Range, on Little Mountain, of Precambrian age: and on the Pleasant View salient; unconsolidated Metasedimentary and metavolcanic(?) rocks, deposits of Pleistocene and Recent age are exposed generally showing remnant stratification or banding, now consisting of quartzite, schist, in the rest of the Weber Delta district. Rocks of arkosite, and injection gneiss. Described Tertiary age are not exposed in the district, but in more detail by Bell (1952) ______10,000+ they are presumed to occur in the subsurface of the PRECAMBRIAN ROCKS basin between the basement rocks of pre-Tertiary The oldest rocks that crop out in the area are a age and the Quaternary deposits. The distribution thick series of Precambrian metamorphic rocks of the consolidated rocks and the Lake Bonneville which are exposed in the Wasatch Range just east Group and younger deposits is shown on the geo­ of the Wasatch fault zone. These rocks are par­ logic map (pl. 1). ticularly conspicuous south of the Weber River. STRATIGRAPHY AND WATER-BEARING PROPERTIES OF THE ROCKS This group of rocks was named the Farmington ROCKS OF PRE-QUATERNARY AGE Canyon Complex by Eardley (1944) and described Rocks of Precambrian and Cambrian age are the in detail by Bell (1952). The metamorphic rocks only rocks of pre-Quaternary age exposed in the constitute a major part of the eastern boundary of mapped area. The Precambrian and Cambrian the ground-water basin, and they probably contain strata that crop out in the area are given in the and conduct large volumes of water which recharge generalized stratigraphic column (table 2) after the aquifers of the Weber Delta district. These Eardley ( 1944). circumstances are discussed in the section on "Re­ charge" (p. 41). TABLE 2.-Generalized stratigraphic column of the consolidated rocks that crop out ln and near the Weber Delta district, Utah Rocks of younger Precambrian age are exposed [Modified from Eardley, 1944, p. 826-827] on Little Mountain in T. 6 N., Rs. 3 and 4 W. Unconformity. (pl. 1). A tillite makes up the larger part of this Feet 1. Limestone and dolomite of Middle and Late(?) isolated mass of rock; the rest is phyllite. These Cambrian age: rocks are part of a much thicker late Precambrian Dominantly limestone with interbedded shale sequence that is exposed at various places in the and dolomite. The limestone is mostly dark Wasatch Range and elsewhere in north-central gray, commonly has wormy markings, and is locally pisolitic or oolitic or both. The Utah (Eardley and Hatch, 1940). They have no unit comformably overlies the Ophir Shale___ 1.375± known significance in the occurrence of ground 2. Ophir Shale of Early and Middle Cambrian age: water in the area, unless they are present in the Shale, brown to olive-green, with a micaceous buried ridge extending southward from Little sheen, and large wormy markings on the Mountain which may be the western boundary of bedding surfaces. Contains numerous arko­ sic and quartzitic layers };1 -1 in. thick. the ground-water basin. Conformably overlies the Tintic Quartzite__ 200 PALEOZOIC ROCKS 3. Tintic Quartzite of Early and Middle Cambrian age: Much of the northern part of the eastern bound­ Massive quartzite, pink and gray, with some buff, red, and purple beds. Contains num­ ary of the Weber Delta district consists of rocks erous conglomeratic layers. The sand-sized of Cambrian age, mostly quartzite and limestone particles are 99 percent quartz, and the or, locally, shale or dolomite. This sequence has pebbles are dominantly of quartz or quart­ been described by Eardley ( 1944). In addition, zite. Conformably overlies Precambrian rocks in some places, but disconformably quartzite and limestone of Cambrian age make up in others ______500-700 the mass of the Pleasant View salient. SURFACE GEOLOGY 13 The oldest rock of Cambrian age is the Tintic locally, strata of the Salt Lake Formation of Quartzite, which forms much of the mountain front. Pliocene age lie below unconsolidated valley fill. Except where shattered, the Tintic Quartzite is Cuttings from 1,900-2,000 feet below the land sur­ nearly impermeable. The Cambrian limestone, on face in the oil test lithologically resemble rock from the other hand, tends to be cavernous, especially outcrops of the Salt Lake Formation in valleys where the rock has been dissolved along faults or tributary to the Great Salt Lake basin. At depths other fractures. Local residents reported that, below 2,000 feet, however, the oil test penetrated early in 1944, excavation in limestone on the Pleas­ sand and gravel similar to material from shallower ant View salient exposed the mouth of a small depths, and the cuttings presumed to be of the Salt cavern which extended an unknown distance into Lake Formation may have been erroneously identi­ the rock. A stream of excess irrigation water, fied or were from cobbles and boulders of Salt Lake having a volume of several cubic feet per second, Formation in a gravel deposit. reportedly was diverted into the excavation for sev­ In summary, rocks of ages between Cambrian eral days. During this time the entire stream was and Pleistocene may occur in the subsurface of the conducted underground by the cavernous limestone, project area, but their presence has not been con­ and water did not reappear downslope from the firmed. excavation. The cavern, therefore, was large or The age of some rocks shown on the geologic had an outlet into permeable material. map (pl. 1) is inferred from scanty information. Near Willard, just north of the Weber Delta These rocks crop out in foothill zones adjacent to district, ground water probably occurs in a lime­ the Wasatch Range and are mostly poorly consoli­ stone, thought to be of Cambrian age, that makes dated mudflow deposits that appear to be older than up much of the crest of the Wasatch front. About most, or all, of the Lake Bonneville Group. Be­ 4,300 acre-feet of water is discharged annually by cause their exact stratigraphic position is unknown, wells near Willard in an area of about 5 square these rocks have been mapped as a unit. The mud­ miles. In addition, a narrow strip of unconsoli­ flow deposits are unsorted and contain an abun­ dated deposits between the Wasatch front and dance of fine material; therefore, they have low Willard Bay yields ground water prolifically, and, permeability and probably contain little ground at times in the spring, ground water discharges as water. Various drillers' logs of wells commonly a sheetflood across saltgrass pastures near the report "gravel and clay" or "boulders and clay," shore of Willard Bay. This ground-water dis­ which probably is older mudflow material buried at charge together with the discharge of the wells in depths of several hundreds of feet in the valley fill. the Willard area, however, do not constitute all the Thus, mudflow material may have been deposited available ground water in the Willard area. Since at many times during the history of the basin. Willard Bay contains fresh water, and surface in­ Mudflow deposition apparently took place under flow is probably negligible, a considerable amount semiarid climatic conditions during periodic violent of fresh ground water seeps into the bay. The storms. During such storms, large masses of Cambrian limestone, where present, therefore, un­ weathered rock material in the Wasatch Range doubtedly is recharged with water from snowmelt became saturated and then flowed into the adjacent and transmits it to the unconsolidated aquifers in basin. the Willard area and probably also in the Weber QUATERNARY DEPOSITS Delta district. Hunt (Hunt and others, 1953, p. 17-24) coined the name "the Lake Bonneville group" for the OTHER PRE-QUATERNARY ROCKS strata of Wisconsin age deposited in Lake Bonne­ Rocks of Paleozoic, Mesozoic, and Tertiary ages ville in northern Utah Valley. Hunt's mapping in crop out in broad areas east of the Wasatch front. Utah Valley confirmed the Lake Bonneville chron­ These rocks, however, are not exposed in the Weber ology established by Gilbert ( 1890), and the pres­ Delta district; the nearest outcrops are several ent study is based on this chronology. miles east of the Wasatch front in canyons such as those of the Ogden and Weber Rivers. Although Sediments of the Lake Bonneville Group, in chronological order, younger to older rocks of Paleozoic and Mesozoic age may be part Gilbert, 1890 Hunt, 1953 of the bedrock surface of the trough, no evidence Stansbury and other post­ Utah Lake is at or above the of this exists. Provo lake deposits. Stansbury level, and Stansbury deposits, therefore, have not Drill cuttings from Hickey oil-test 2, (B-3-1) been recognized; post-Provo 36ddd, near Farmington, indicate that, at least deposits are scattered and thin. 14 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

Sediments of the Lake Bonneville Group, in chronological order, Alpine Formation and in other places are absent. younger to older-Continued At a few places in the Lake Bonneville basin, Unconformity notably Stansbury Island, Gilbert (1890, p. 134- Provo-stage deposits. Provo formation. 135, 186) recognized a conspicuous shoreline 300- Unconformity Bonneville-stage deposits. Bonneville formation. 350 feet lower than the Provo level of 4,800 feet. Unconformity? To explain this shoreline, he postulated a post­ Intermediate-stage deposits. Alpine formation. Provo rise in water level to a level he designated as Unconformity Stansbury. Gilbert offered no reason for a still­ Pre-Lake Bonneville deposits. Pre-Lake Bonneville deposits. stand at the Stansbury level. PROBLEMS IN SEPARATING AND IDENTIFYING FORMATIONS OF Gilbert's correlation of wave-cut benches, beaches, LAKE BONNEVILLE GROUP bars, spits, and other massive deposits with lake A simplified discussion of Gilbert's ( 1890) stages was based principally on topographic posi­ chronology of Lake Bonneville will aid in the tion or altitude. Deposits at or just below the understanding of some of the problems. Bonneville shoreline, at about 5,200 feet in the The first stage of Lake Bonneville was the Inter­ Weber Delta district, were presumed to be asso­ mediate stage, during which the Alpine Formation ciated with the Bonneville stage of the lake. De­ (named by Hunt in Hunt, and others 1953, p. 17) posits at about 5,100 feet were recognized as being was deposited. The lake apparently stood at about older than the deposits at the Bonneville level and 5,100 feet for a long time, depositing gravel and were correlated with the Intermediate stage of the sand as beaches, deltas, spits, and other shore and lake, so named because of its position intermediate near-shore deposits, and laying down silt and clay between the Bonneville shoreline and the lower in deeper water throughout most of the basin. Provo shoreline at about 4,800 feet. Thick and But it must not be assumed that deposits were laid extensive "embankment" (Gilbert's term) deposits down over the whole area covered by water, for below but near the Provo shoreline were correlated in many places, waves and currents in the lake with the Provo stage of the lake. eroded vast areas that were covered by older de­ After each of the lakes receded, its discontinuous posits. Not only did the littoral and offshore cur­ deposits were partly removed by subaerial erosion, rents plane off large volumes of preexisting alluvial were covered in some places by subaerial deposits, or lake deposits, but in many other areas these or were reworked by the wind, mass wastage, or currents kept deposition at a minimum. Thus, by soil-forming processes. In places subjected to when the Alpine lake withdrew, perhaps to com­ subaerial erosion after the Provo lake receded, the plete desiccation, the Bonneville basin was covered deposit exposed might be Provo Formation, a post­ by thick deposits of the Alpine Formation in some Alpine subaerial deposit, Alpine Formation, or any areas; but in other areas, older deposits were ex­ one of the pre-Alpine unconsolidated or consoli­ posed or were covered by a few inches to a few dated rocks. Thus, identifying a deposit by its feet of Alpine deposits. altitude obviously is not a completely reliable When the basin filled again in Bonneville time, method. the water rose above the Alpine shoreline and over­ Hunt's separation of the deposits above the Stans­ flowed through an outlet in Red Rock Pass at the bury level in northern Utah Valley was based on north end of Cache Valley in southeastern Idaho. "superposition of beds, lateral tracing of contracts The Bonneville lake was short lived and its prin­ between formations, observations of lateral and cipal deposits are shore and near-shore gravel and vertical changes in lithology" (Hunt and others, sand near the Bonneville level of about 5,200 feet. 1953, p. 4). Hunt's discussion of the mapped units When the Bonneville lake overflowed, its level and his map indicate that the Alpine and Provo dropped quickly, and in 25 years or less (Gilbert, Formations have shore and near-shore facies of 1890, p. 177) the lake dropped to the Provo level, gravel and sand that grade lakeward into silt and where the river outlet reached a bedrock barrier at clay, whereas the Bonneville Formation was "recog­ about 4,800 feet. How long the lake remained at nized only as a thin and discontinuous beach the Provo level is unknown, but below 4,800 feet are deposit along the high shoreline and in a spit at extensive shore, near-shore, and deep-water de­ the Point of the Mountain" (Hunt and others, 1953, posits that blanket much of the area. Like the p. 20), where the deposit is about 300 feet thick. Alpine deposits, the Provo deposits were laid down Jones and Marsell (1955, p. 94-96) have reinter­ in discontinuous beds that in places cover the older preted the 300-foot-thick deposit as a compound spit SURF ACE GEOLOGY 15 related to the Alpine Formation rather than to the everywhere in sediments of the Provo Formation. Bonneville Formation. Further discussion of the fossil record appears To date, no one has reported any physical criteria later in the section on "Paleontology" (p. 31). by which the several formations composing the Various attempts (Morrison, 1952a, b; Richmond Lake Bonneville Group can be distinguished from and others, 1952) have been made to use Pleistocene each other. In contrast to other areas in the coun­ soil horizons as markers within sequences of lacus­ try, where Pleistocene formations are sometimes trine strata. Although this method was not used identified by differing degrees of chemical break­ in the Weber Delta district, it appears to be a down of pebbles in gravels composing parts of the promising approach to the zonation of the Lake formations, there appears to be no difference in Bonneville Group. degree of weathering of the pebbles from the sev­ The environments of deposition during Pleisto­ eral formations in the Lake Bonneville Group. It cene time in the East Shore area were different is probably a safe generality to state that the Al­ from those of many other parts of the Lake Bonne­ pine Formation is predominantly finer grained than ville basin. The area faces the widest part of the any of the others, but Hunt describes a gravel mem­ ancient lake and thus was subject to maximum ber within the Alpine Formation, and gravel and wave activity at each stage of Lake Bonneville. sand that appear to belong to the Alpine Formation Shore features developed on unconsolidated ma­ are also found in the Weber Delta district. Simi­ terials were subject to rapid and extensive rework­ larly, silt-clay phases of the Provo Formation have ing to a degree perhaps not encountered anywhere been observed in various parts of the Bonneville else in the basin. The consolidated rock of the Basin, including the Weber Delta district. In con­ Wasatch Range is almost completely covered by sequence, the textural criterion is not uniformly sediments from the present valley floor to the applicable as a device for separating one formation Bonneville shoreline; therefore, if wave-cut notches from another. were formed in the consolidated rock at altitudes Fossil criteria by which to separate one forma­ lower than that of the Bonneville shoreline, the tion from the other are extremely scarce. One notches are now masked by unconsolidated ma­ species of ostracode appears to be confined to the terial. The result of these conditions is that many Provo Formation; but unfortunately, it is not found shore features prominently developed in other parts

TABLE 3.-Pebble-count analyses of gravel in the Provo and Alpine Formations of the Lake Bonneville Group

Number of pebbles Location and Rounded Angular number of pebbles Name Percent Spher-~ Elon- Cyl- Irreg- Irreg- total I oid Disk I gate I inder I ular Slab ular 1 Cuboid I Blade disk I I I

Provo Formation (B-5-1) 22dd: 213 pebbles from gravel Quartzite 82 34 35 24 43 27 5 4 3 ------pit at crest of hill, north side of Weber Chert 3 1 1 2 1 ------1 Canyon. Quartz breccia 1 ------1 ------1 ------Quartz 5 1 1 ------2 3 1 1 1 ------Volcanic rock 1 ------1 ------1 1 ------Gneiss 8 1 1 ------4 3 2 1 5 ------(B-5-1) 22dc: 110 pebbles from gravel Quartzite 87 22 18 11 20 15 5 4 2 pit on rim of Uintah Bench about 0.2 Chert 2 2 ------mile west of location named above. Limestone 3 2 ------1 ------Quartz Volcanic rock Gneiss !1::::=: ----~- ::::J:::r: :::::: ::::~: ::::i: ::::i: :::::: Alpine Formation (B-5-1) 20: 118 pebbles from marly con- Quartzite &9 24 16 10 16 I 9 2 2 1 1 I I I glomerate on flank of Uintah Bench Chert 4 ------1 1 2 2 ------about 200ft above Weber River level. Limestone 2 1 1 ------Quartz 6 1 1 ----r~----r 2 ------1 Gneiss 19 1 2 3 9 2 2 1 (B-5-1) 20: 112 pebbles from poorly con- Quartzite 80 18 21 13 2 3 1 ------solidated gravel 150 yd east of above Chert 7 2 1 3 ------sample and presumably stratigraphi- Limestone 2 1 1 ----=-1 2~ 1 cally equivalent. Quartz 3 1 Gneiss 8 1 ----~r T 1 1 2 1 I t======16 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT of the Lake Bonneville basin cannot be recognized in the East Shore area. 80 r---- 0 Clay smaller than 0.005 mm; deter------....------1 In the Weber Delta district, neither prominent mined by hydrometer analysis ' shorelines nor deposits were recognized that might 70~------f-~ r------~-- be assigned to the Stansbury. Comparison of the 0 X 60~--~0L~n-~------~--~ 0 ' X geologic map of the district (pl. 1) with a topo­ X 0 X 0 X graphic map indicates that the interval 4,450-4,500 u X 0 feet is underlain in most places by coarse-gravel 0 0 X and sand, or sand-facies of the Alpine or Provo

Formations; locally, the interval is underlain by X 0 v finger grained material of Recent age. The Alpine 20~------~0-~ and Provo Formation facies extend above and be­ Blocky clay in the Alpine Formation 0 0 low the contours that enclose the Stansbury inter­ 10 ~----has silt and clay percentages within ----'"'-----0 ----i val. Under these circumstances recognition of zone bounded by dashed lines O ..1 ..1 ..1 ..1 ..1 ..1 I I Stansbury deposits would be unlikely. If deposits 1 2 3 4 5 6 7 8 9 10 11 12 13 1415 16 17 18 1920 21 were formed by a Stansbury-stage lake in the SAMPLE NUMBER

Weber Delta district, they remain unrecognize

Measured section of the Alpine and Provo Formations-Continued Feet 3. Gravel ______10

Total thickness of the Provo Formation______14.5 Disconformity. Alpine Formation: 4. Mostly silt with fine sand, all thinly laminated ___ _ 40 5. Sand, clayey, with interbedded iron-stained sand; water seeps out above this zone ______3 6. Clay with some interbedded silt and sand ______4 7. Sand, fine, reddish with brown silty bedding sur- faces; some interbedded silt and clay ______30 8. Clay, thinly laminated, shaly, plastic when wet_ __ 1 9. Sand, fine to medium ______2 10. Sand, well-cemented, pink ______.5 11. Sand, fine to medium; three intercalated clay beds less than 1 in. thick ______15 12. Silt______1 13. Sand, fine ______2 14. Clay; shaly when dry, plastic when wet______.1 FIGURE 5.- Cliff-forming clay of the Alpine Formation, sec. 15. Sand, fine ______3 21, T. 5 N., R. 1 W., in a canyon cut into the Weber Delta. 16. Clay; light gray at base, brown at top; iron-stained_ .5 About 35 feet of strata is shown in the photograph. 17. Sand, fine, silty ______2 18. Silt; shaly partings; cream-colored ______.2 in the district is a slabby salmon-pink to reddish­ 19. Sand, fine ______---- 6 20. Sand, clayey ______-- .3 brown well-consolidated clay that is particularly 21. Sand, fine __ ------2 well displayed on the Weber Delta in the first sev­ 22. Clay, light-brown, shaly; plastic when wet______.2 eral miles downstream from the mouth of the 23. Sand, mostly fine; some clay in a few beds ______8 canyon of the Weber River. This unit, which is 24. Silt and very fine sand ______.5 25. Sand, mostly fine ______-- at least 80 feet thick in some places, is a prominent 1 26. Silt and fine sand, clayey; water issues above this cliff-forming member (fig. 5) on the north side of un~ ------.5 the present river valley cut into the Weber Delta. 27. Sand, fine to medium, light-brown to bufL ------~ Less-well-consolidated strata, largely sand, silt, Base of the Alpine Formation concealed in deposits of and clay, also assigned to the Alpine Formation, windblown sand. underlie much of the district, but they are most Total measured thickness of the Alpine commonly exposed only just west of the foothills Formation ______------135 bordering the Wasatch fault zone. West of the roadcut described above, the Alpine North of the Weber River, U.S. Highway 89 Formation is exposed in gullies and canyons incised climbs from the level of the Weber River to the into the Uintah Bench. In this area the Alpine Uintah Bench, about 300 feet higher. The roadcut grades rapidly westward from sand to a sequence exposes an almost unbroken sequence of medium­ of salmon-pink well-consolidated slabby silts and grained sand beds with a few thin intercalated clays. Toward the toe of the delta this sequence clay-silt layers. The topmost 15-20 feet of the sec­ of sediments changes first to a section of somewhat tion is gravel, here interpreted as part of the Provo coarser thin-bedded (1-3 in. beds) silt, rather Formation, and the sand and clay composing most poorly consolidated and intercalated with sand and of the section probably are part of the Alpine For­ thin lenses of gravel, and then, near the toe of the mation. The sequence is given in the following delta in the vicinity of Riverdale, to a sand. The measured section: thin-bedded poorly consolidated silt intercalated with sand contains the fossil Cyther·issa cf. C. Measured section of the Alpine and Provo Formations lacustris ( Sars), which is here considered charac­ ISecs. 22 and 23, T. 5 N., R. 1 W., in a conspicuous roadcut on the north side or U. S. Highway 89. Section measured by P. E. Dennis (unpub. data, 1951); field teristic of the Provo Formation (p. 31). The silt checked and modified by J. H. F eth in 1954. Color o[ fine-grained unit is buff to reddish tan when not otherwise stated] and sand probably were deposited during Provo Present land surface. time as a sand bar against the toe of an older Provo Formation: Feet delta. During the final phase of Provo time, a 1. Soil, gray______0 . 5 deposit of gravel, not exceeding 20 feet in thickness, 2. Clay, silty, brown; concentrations of calcareous material near the base______4 was deposited across the entire delta area. 18 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

An exposure in a canyon incised into the Uintah Measured section of the Alpine and Provo(?) Formations- Continued Bench in sec. 21, T. 5 N., R. 1 W., illustrates an­ 50 yd south of the location above. The marl Feet other difficulty in correlating formations using the (unit 5) is at both localities. criterion of altitude alone. In that canyon, salmon­ Detailed description of a 1-ft zone in unit 5. The top of the detailed section is 2.00 ft above pink well-consolidated silt and clay, which by all the base of the marl. evidence are part of the Alpine Formation, have a. Marl, gray papery; dark- and light-gray been folded and dragged along a high-angle fault streaks subparallel to bedding______0 .18 that strikes approximately northeast along the axis b. Marl, dense, dark-gray, organic______. 07 c. Marl, like a ______. 20 of the canyon. The tQtal displacement on the fault d. Marl, like b______.01 is about 175 feet; the east side is down thrown e. Marl, like a ______.14 relative to the west side. This fault is further f. Clay, olive-green, hair-thick laminae; described on page 22. A displacement of this irregular rusty stains______.10 g. Marl, like a ______.20 magnitude could bring shoreline deposits of, for h. Clay,likef______.10 example, the Alpine Formation below the Alpine Base of detailed section is 1.00 ft above base of unit 5. shoreline and result in such strata being mistakenly Base of marl, unit 5. designated as Provo. The section on the west wall 6. Gravel, reddish-brown overall; calcareous cement; of the canyon in sec. 21 is described below. This well-sorted; 6 in. bed of sand about halfway up from base, marked by a band of limonite section is pictured in figure 5, and mechanical staining______12 analyses of samples from it are included in the 7. Clay, dark-reddish-brown, finely laminated; 2-3 data of figure 4. in. layer of pebbles at the base; a sandy stringer in the upper foot, 7.:l in. thick; limonite staining in the upper 1}1 in.______5 Measured section of the Alpine and Provo(?) Formations ISEJ::( sec. 21, T. 5 N ., R. 1 W., on the northwest wall of a canyon cut into the 8. Sand, tan and gray; tan sand is fine, gray is pmtah Bench nor th of the We.ber River. Field relations indieatc that the canyon coarse; ripple marks with an amplitude of lS cut along a northeast-irendmg fault; the southeast block is downthrown about 175 f t relative to the northwest block. ThP section described has not been about 1 in. in some beds; base of unit is flat_ _ 4 fo~nd on the southeast wall of the canyon. The base of the prominent marl umt was used to correlate the part of the section at the first location with that 9. Pebbles and sand, alternating______3 at the second location. Measured by J. H. F eth and P. S. Moore[ 10. Clay; basal 1/ ft rusty brown, rest of unit red; Present land surface. plastic when wet. ______4 5 Provo(?) Formation: Feet 11. Sand, tan, medium, well-sorted; sparse laminae 1. Conglomerate, gray overall; consists of meta­ of red silt and clay, !4 - % in. thick; base buried morphic rocks, orthoquartzite, quartz, lime­ in more than 4 ft of slopewash, assumed to be stone, sandstone, and chert in a heavily at level of small stream draining the canyon_ _ 13 calcareous silty matrix; discoidal snails abund- Total thickness of the Alpine Forma- ant, other snails present______10 tion ______l01.5-104.5 Angular(?) unconformity. Alpine Formation: Sand and gravel of the Alpine Formation are 2. Clay, well-consolidated; similar to unit 3 but exposed principally in areas close to the mountain crumpled and contorted, bedding nearly indis- front, and some of the water in the streams that tinguishable ______12-15 drain the west front of the Wasatch Range moves 3. Clay, pinkish-tan, very well sorted, well-consoli­ into these unconsolidated sand and gravel deposits dated, calcareous cement; forms prominent cliffs; bedding planes flat and sharply-defined, and enters the ground-water reservoir. In some causing slabby weathering; beds generally 1- 6 areas, such as in sec. 23, T. 5 N., R. 1 W., along in. thick; brick-red interbedded laminae, }1- 1 in. U.S. Highway 89, local bodies of perched ground thick; smooth-shelled ostracodes (Candona sp.) water in the sand and gravel of the Alpine Forma­ common in some beds, other ostracodes sparse; tion discharge at the faces of canyon walls or road­ a few plant-stem imprints, none identifiable__ 32 4. Clay, well-consolidated, red, with interbedded cuts. The water moves downward to the upper reddish-tan sand and silt; mud curls at top of surface of a clay unit of the Alpine Formation and unit suggest deposition under playalike con- then moves laterally to a point of discharge. The ditions______3 clay in the Alpine characteristically has a low per­ 5. Marl, light- and dark-gray laminae with some black (organic) and green (clay) laminae; meability and greatly retards passage of water. mostly papery weathering but some light-gray On the Weber Delta just north of the Weber beds weather to white dust; numerous snails; River (the Uintah Bench) a few narrow ridges and ostracodes, mostly smooth-shelled; fish spines; an isolated hill, which rise about 75 feet above the many unidentifiable plant imprints; seeds common in some laminae______13 general land surface, have been mapped as clay The following part of the section was meas- (pl. 1). These ridges and the hill consist of fine­ ured in a trench dug through slope wash about grained salmon-pink rather well-consolidated sand SURFACE GEOLOGY 19 and silt and, in part, of clay of similar color and Provo Formation caps terraces below 4,800 feet and degree of consolidation. The ostracodes in these is commonly 10-20 feet thick, although locally it is beds are characteristic of silt and clay of the Alpine 50-100 feet thick. Formation; these strata are, therefore, correlated The coarse material of the Provo Formation with the silt-clay phases of the Alpine. absorbs water that falls on or runs across its sur­

Bonneville(?) Formation face, such as precipitation or irrigation on the A series of sand and gravel deposits at altitudes small areas of farmland and much broader areas ranging from 5,100 to more than 5,200 feet imme­ of Ia wns and gardens on the benchland of the diately adjacent to the consolidated rock of the Weber Delta district. Such recharge percolates Wasatch Range may be closely equivalent to downward through the Provo Formation until it strata mapped in northern Utah Valley (Hunt and reaches the finer materials in the underlying Alpine others, 1953, pl. 1) as the Bonneville Formation. Formation, and then it moves laterally. Locally, These outcrops are characteristically elongated then, areas covered by Provo deposits are recharge north-south, parallel to the Wasatch front, and areas for bodies of perched ground water on the are thin, commonly on the order of a few feet to benchlands, and a relatively shallow artesian aqui­ 20 or 30 feet in thickness. In the Weber Delta fer south of the Weber River and west of the town district no clear unconformity or disconformity has of Roy is probably recharged through these de­ been found at the base of these sand and gravel posits. Some water moving through the Provo units and therefore the Bonneville(?) cannot be dif­ deposits may also reach deeper aquifers. ferentiated from the Alpine. Some of these high­ RECENT DEPOSITS level sand and gravel deposits are shown on the Sediments of Recent age are at the surface in geologic map (pl. 1) as sand and gravel of the Bon­ much of the Weber Delta district. The thickness neville(?) and Alpine Formations undifferentiated. of the Recent deposits is not known accurately, but As these deposits are commonly rather well sorted it is probably in the order of a few to 40 feet. No and are characteristically uncemented, they are fossils are known by which these deposits can be exceptionally receptive to recharge. Their small distinguished from lithologically similar sediments areas of outcrop and their disconnected nature, in the Provo or Alpine Formations. Lacustrine or however, restrict their significance in the total flood-plain deposits of Recent age occupy extensive ground-water picture of the district. areas at altitudes between 4,200 and 4,300 feet; Provo Formation consequently, these deposits blanket the surface in Three lithofacies-gravel, gravel and sand, and areas of artesian discharge. sand-are recognized in the Provo Formation, the In areas mapped as hardpan (pl. 1), silt and sand youngest of the Lake Bonneville Group to be recog­ have been loosely to tightly cemented, mostly by nized in this study. Adjacent to the mountains, a lime. The resulting cemented sand is locally so considerable area is underlain by material mapped hard that it is difficult to break with a sledge ham­ as gravel and sand of the Provo Formation, and mer. Such cemented layers range in thickness from this material accepts recharge that eventually less than 1 foot to as much as 5 feet and charac­ moves to the ground-water reservoir. This gravel teristically occur as elongated strips. Preliminary and sand, as well as sand of the Provo Formation, tests made in connection with the drainage program also covers broad areas on benchlands at about of the Weber Basin Project show that despite their 4,800 feet, typical of which are the Uintah Bench cemented character, many of the hardpan deposits and the bench south of the Weber River on which are still quite permeable. Hill Air Force Base is located. In local areas Recent sand occupies various areas in the adjacent to the mountains and on the benchlands, lowlands, but perhaps the most prominent de­ gravel of the Provo Formation has been mapped posits are two elongated ridges that extend gen­ as a separate unit. On the benchlands, strata of the erally northeast-southwest, west of the city of Provo are characteristically about 10-30 feet thick. Ogden, in Tps. 5 and 6 N., R. 2 W. The tops of At the Provo stage the lake planed the older, higher, these ridges are a few feet to about 10 feet above deltaic materials deposited during the Alpine stage the lowlands on either side and are here interpreted to a level bench at about 4,800 feet. The gravel and as bars formed when lake water stood only a few sand of the Provo Formation were deposited mostly feet above the present land surface. As the sand as beach and shore features, probably during reces­ ridges are highly permeable, irrigation ditches leak sion of lake from the Provo stage. Sand of the profusely where they cross the ridges, thus adding 20 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT to waterlogging of adjacent clay lowlands. In a let, at about 4,200-4,210 feet, which marks the limit few places small bodies of perched water are in of the wave erosion of the modern lake. This mod­ the sand ridges. The soil on the ridges is generally ern clay is estimated (Eardley and Gvosdetsky, a sandy loam, suitable, when irrigated, for raising 1960) to be less than 10 feet thick, and it is thinnest most crops common to the area. The adjacent low­ at the upper (eastern) margin of the deposit. The lands in many places are water-soaked and en­ clay is characteristically dark gray, green, or black crusted with various amounts of salts, locally with and has a fetid odor and a relatively high organic sodium carbonate ("black alkali") or with sodium content derived largely from material washed into chloride. Prosperous farms are on the sand ridges, Great Salt Lake or brine shrimp (Artemia) re­ whereas the lowlands are either barren or support mains. The clay, at least in the top 4 feet explored saltgrass pasture, pickleweed (Allenrolfea occiden­ in this investigation, is thoroughly impregnated tal,is), or other highly salt-tolerant plants of no with salts, principally sodium chloride. The low economic value. Some of these lowlands probably rate of evaporation from the salt-encrusted barrens could be reclaimed by drainage and leaching. underlain by the clay, discussed later in the section Areas underlain by clay, mostly in the low-lying "Evaporation and evapotranspiration studies," western part of the Weber Delta district, will have shows that the rate of upward leakage of artesian to be drained before they are suitable for agricul­ water through the clay is very slow. The clay is ture; reclamation of these areas is vital to the exposed at the surface in a rather narrow strip success of the Weber Basin Project. In some along the western boundary of the district (pl. 1). places, however, the clay is rather dense and is sat­ It extends many miles westward under the present urated with sodium chloride. If the water table is basin of Great Salt Lake, however, and probably at or very near the land surface in such places, is a seal which separates the brine of Great Salt the sodium chloride-saturated clay has become Lake from the water in the artesian aquifers under impregnated with sodium carbonate. Land-classi­ the lake. The extent of the fresh-water aquifers fication data show that locally the alkali impreg­ under the lake is not known; therefore, the role of nation and saturation with other salts has destroyed the clay in determining this extent cannot be the soil structure and the land is considered evaluated. unreclaimable. In other areas the land probably STRUCTURE can be reclaimed and used for agriculture by drain­ FOLDS ing it and by applying excess irrigation water, The few folds in the Pleistocene deposits in the preferably of a calcium magnesium bicarbonate Weber Delta district are small. The largest fold type. observed is related to drag on a normal fault in Local areas are occupied by Recent gravel which the SE14 see. 21, T. 5 N., R. 1 W., in a canyon in the apparently marks former channels of the Weber Uintah Bench. There, in the immediate vicinity of River or other major streams that crossed the area. a normal fault (discussed below), clays interpreted Inasmuch as the gravel is thin and is underlain by as of Alpine age have been dragged 10-20 feet finer materials, it has no effect on the occurrence of through an arc of about 45 o. ground water. Most of the other folds observed have amplitudes Near the mountains, the youngest sediments ex­ only of inches. They represent deformation during posed are characteristically coarse. In river chan­ compaction of the sediments or minor adjustments nels the most recent deposits consist of boulders, to stresses, such as small slippages. A sandy se­ cobbles, gravel, and coarse sand, which are highly quence exposed at several places in T. 6 N. displays receptive to recharge. Elsewhere, however, the folds that in a few places have amplitudes of 1-2 deposits consist of mud rock flows, the material of feet. At this location the intricate nature of the which ranges in size from silt and clay to blocks the folding, the presence of graded bedding, and other size of small houses. Thus, although the coarse evidence lead to the conclusion that this sequence fraction predominates, in some places there is and a few others in the area, are turbidity current enough fine interstitial material to reduce greatly deposits (Feth, 1955, p. 48-49). the permeability of the mud rock flows. MAJOR FAULTS The western boundary of the Weber Delta dis­ The largest geologie structures in the area are trict is underlain by clay deposited by Great Salt faults of regional magnitude. The Wasatch Range Lake. The clay extends from the 1956 shoreline is separated from the valleys at its western base by at about 4,197 feet to the base of the lowest scarp- a great fault (Gilbert, 1928, p. 11) that extends for STRUCTURE 21 some 150 miles, locally marking the eastern border Total relief from movement along the Wasatch of the Basin and Range physiographic province and fault is not known. It may exceed 10,000 feet also the eastern boundary of Meinzer's ( 1923a, adjacent to the Weber Delta district, however, as pl. 31) southwestern bolson ground-water province. some peaks of the frontal range near the fault zone It is a normal fault, downthrown to the west, and are more than 9,000 feet above sea level and geo­ the fault surface dips to the west from about physical data indicate that near the fault, bedrock 20 ° to as much as 70 ° and averages about 33 ° is on the order of 2,000 to possibly as much as (Gilbert, 1928, p. 22). 5,000 feet below sea level. Under certain conditions of light, multiple fault facets may be seen along the Wasatch fault and are best seen immediately south of Weber Canyon. There (fig. 6) the impression is that the youngest , and most marked triangular facets of the Wasatch fault are themselves on an earlier larger fault facet, dissected by erosion into two spurs. The older "facet" is at a flatter angle than are the most recent facets. It is also possible to visualize a still older "facet," higher on the range and at a still flatter angle, whose downward projection may in­ clude four of the recent facets and the two facets of intermediate age. These relations are shown in figure 6. If all the facets were formed by faults, then there is evidence of at least three periods of major uplift along the Wasatch fault. The Wasatch Range also would appear to have been successively tilted eastward, causing the fault facets of each period of movement to lie at a flatter angle than those of the following period. The highest semiplane surfaces on the Wasatch front may be remnants of even older facets, but they have been interpreted (Eard­ ley, 1944, p. 877) as an ancient erosion surface graded to the ancestral Weber River. It is also possible that the surfaces here interpreted as older facets represent erosion surfaces. The fact that the Bonneville shoreline crosses the lowest (young­ est) facets about half way from their bases sug­ gests that they are not facets cut by waves, a pos­ sibility suggested by Eardley (1944, p. 888) for the ongm of some facets. The Wasatch fault probably is not a single break, but rather it is a zone of shattering, move­ ment, and slippage a mile or more in width. Locally, this zone has considerable influence on the occurrence of ground water. In certain areas, the frontal-fault zone apparently serves as a channel­ way along which warm mineralized water rises from considerable depth, such as at El Monte FIGURE G.-Photograph of multiple fault facets on the west Spring at the mouth of Ogden Canyon and at front of the Wasatch Range near the mouth of Weber Canyon. Utah Hot Springs at the west end of the Pleasant Upper, View southeastward across the flood plain of the Weber View salient. River. Lower, Sketch from the photograph above showing interpretation of the facets. (1) oldest facet; (2) facet of Topographic and geophysical evidence suggests intermediate age; (3) youngest facet. that an east-trending fault of regional magnitude 22 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT may pass through the Weber Delta district at about though less mineralized, than the saline water ris­ the southern boundary of the exposures of Cam­ ing along the Wasatch fault zone. The water brian rocks on the Pleasant View salient (pl. 1). from Hooper Hot Springs, in particular, probably Topography and gravity studies (D. R. Mabey, rises along a fault because of its high temperature, written commun., Mar. 22, 1956) indicate that the high salinity, and relatively high boron content bedrock surface dips very steeply just south of the ( 1.2-4. 7 ppm (parts per million) ) . Pleasant View salient, as though downthrown MINOR FAULTS along a major normal fault. In theSE%, sec. 21, T. 5 N., R. 1 W., a northeast­ In addition, a fault, downthrown to the south southwest trending canyon is cut into the Uintah with a displacement on the order of several thou­ Bench. The canyon is less than a quarter of a sand feet, cuts Paleozoic rocks near the south end mile long, but a shallow trough marked by swampy of Promontory Point, about 10 miles west of the ground extends for more than a mile northeastward west boundary of the district (Richard Olson, oral from the head of the canyon. The northwest wall commun., 1956). This fault zone can be projected of the canyon (fig. 5) displays a section of hard by eye, according to Olson, eastward along the slabby clay considered characteristic of the fine­ southern boundary of the Pleasant View salient grained facies of the Alpine Formation. Below the and up North Ogden Canyon. However, additional clay is 13 feet of white and gray marl. These beds evidence will be required to confirm the presence have not been recognized on the southeast wall of of this structure. the canyon. At the upper end of the canyon, the A major north-south fault may trend just east clay is folded through an arc of about 45° and of Little Mountain (pl. 1). Little Mountain con­ dragged downward 10-20 feet on the southeast. sists of Precambrian tillite and phyllite (Eardley About a quarter of a mile to the east and at an and Hatch, 1940, p. 807) and is more than 10 miles altitude about 175 feet lower, a farm road cut into west of the nearest point in the Wasatch Range the Uintah Bench exposes strata equivalent in li­ where rocks of such age are exposed. Many wells thology and fossil content to the slabby Alpine clay in the area between Little Mountain and the that is exposed in the canyon in sec. 21. The Wasatch front penetrate 500-750 feet of unconsoli­ canyon, therefore, probably is located along a high­ dated sand, silt, and clay, and the Bureau of Recla­ angle fault, downthrown about 175 feet to the mation test well 4A, (B-6-3) 15dad-1, was drilled southeast. A projection of the trend of the canyon 1,210 feet without penetrating bedrock. Further southwestward across the Weber River valley to south, the Bureau's test well 5B, (B-5-2) 16dcd-2, the benchland south of the river is marked by a was drilled 3,007 feet without penetrating bedrock. notch and gully. The fault, therefore, may con­ Geophysical data imply that as much as 6,000-9,000 tinue for 4 or 5 miles. feet of unconsolidated material is in the trough. North of the mouth of Ogden Canyon in sec. 22, Westward, the next exposure of phyllite is at T. 6 N., R. 1 W., a small fault parallel with, and Promontory Point, which is separated from Little presumably related to, the Wasatch fault displaces Mountain by a large arm of Great Salt Lake. sediments of the Alpine Formation. The fault is Little Mountain, therefore, is either a horst, a peak probably downthrown to the west, but the magni­ on the west edge of a block downthrown along the tude of displacement is not known. Wasatch fault at its eastern margin and tilted to the east, or a klippe remaining after erosion of a SUBSURFACE GEOLOGIC STUDIES sheet overthrust from the west. However, the Strata of the Lake Bonneville Group are within great thickness of valley fill suggests that there has a 1,200-foot topographic interval from the Bonne­ been vertical displacement between Little Mountain ville shoreline at an altitude of 5,200 feet to about and the Wasatch front. Little Mountain is prob­ 200 feet below the present surface of Great Salt ably a horst because seismic data indicate a fault at Lake, or at an altitude of about 4,000 feet. The its east flank. maximum thickness of the Lake Bonneville Group Data on quality of water also suggest a fault on is not accurately known, but it is probably 200- the east flank of Little Mountain. Many seeps that 350 feet. produce sodium chloride water fall on several Geophysical information implies, however, that northwest-trending lines between Little Mountain the unconsolidated fill is at least 6,000 feet thick and Hooper Hot Springs to the southeast (fig. 12). in the deepest part of the trough underlying the The spring water is similar in composition, al- Weber Delta district. Thus, the Lake Bonneville SUBSURFACE GEOLOGIC STUDIES 23

Group represents only a relatively short part of the quired to file logs with the Utah State Engineer; history of the Bonneville Basin. The geophysical hence, a large body of well-log information is avail­ data suggest, however, that the entire thickness able for the Weber Delta district. Using the logs consists of materials similar to the lake-deposited of 300 wells, a peg model was made which illus­ sediments of the Lake Bonneville Group. trated the gravel, sand, silt, and clay beds in the The deposits of the Weber Delta, to depths of at subsurface of the district. These well data and least 800 feet, consist predominantly of sand and data obtained from other well logs were used to gravel extending fanlike from the mouth of Weber prepare maps showing the distribution of coarse Canyon (pl. 5) over an area of about 140 square and fine materials in two depth zones (pis. 2, 3). miles. Much of this material is below the base of Although the accuracy of the drillers' logs varies, the Lake Bonneville deposits, thus indicating that the logs provide much useful information which conditions near the Weber Delta during pre-Lake can be used to determine the generalized distribu­ Bonneville Pleistocene time were not significantly tion of materials in the subsurface. different from conditions during Lake Bonneville During the period 1952-56, drill cuttings were time. obtained from six test wells drilled by the Bureau During times of glaciation in the Pleistocene of Reclamation and from several privately owned Epoch much material was eroded in the mountains wells. by the glaciers, and runoff carried this material Two geophysical studies were made during the into the valley and deposited it in lakes. During project; one was a gravity survey made by D. R. interglaciations the climate was probably similar Mabey, of the U.S. Geological Survey, and the other to the present semiarid climate, and most of the was a shallow-reflection seismic survey made co­ material moved into the basin was transported by operatively by the Geological Survey and the Bu­ floods caused by summer storms or spring runoff. reau of Reclamation. During parts of Pleistocene time, probably prin­ PEG MODEL AND DRILLERS' LOGS cipally during interglaciations, loess was probably The peg model made from 300 drillers' logs blown into the area, deposited on the mountain showed clearly that no series of beds can be traced slopes, and later eroded and deposited in the basin, over long distances in the Weber Delta district. overlapping the sands and gravels of earlier times Rather, the valley fill consists of an intricately (H. D. Goode, oral commun., Aug. 1963). interfingering mass of lenticular or wedge-shaped The coarse material originally eroded by glaciers strata of gravel, sand, silt, and clay. Little is cannot be distinguished from other fragments in known about strata deeper than about 1,000 feet drilling samples; so the glacial sequence cannot be below the land surface because only four holes are determined by studying the valley fill. Glaciation known to have been drilled to greater depths in the occurred several times in the Wasatch Range dur­ district. North-south cross sections show a few ing Pleistocene time, however, and the material fairly continuous zones, but along east-west cross originally eroded by glaciers may make up a sig­ sections the absence of continuous beds is striking. nificant part of the deposits in the Weber Delta Apparently many of the sand, silt, and clay beds district. Periodic uplift of the Wasatch Range were distributed by lake currents in bands paral­ probably occurred during much of Tertiary and leling the shoreline of Lake Bonneville and thus Quaternary time; therefore, the range has long been are fairly continuous from north to south. Per­ a source of coarse material. haps it is more difficult to recognize individual units These general conclusions do not apply at any that extend from east to west because the texture specific point in the district because variations in of any unit probably becomes finer from the Jnoun­ environment in the basin resulted in widely differ­ tains toward the lake. Gravel lenses may be more ent types of sediments at different places. Because continuous from east to west than from north to the ground water in the district occurs principally south, however, because the large fragments would in the unconsolidated deposits, however, much effort be less readily spread by lake currents and more was spent in determining the thickness and dis­ likely to remain as originally deposited, in deltas tribution of these deposits. Information was ob­ or alluvial fans laid down by the mountain streams. tained from well logs and from test-hole, gravity, Among the largest of the known groups of gravel and seismic data. These data are discussed in the lenses are two continuous zones that extend west­ following sections. ward from the mouth of Weber Canyon. These Since 1935, water-well drillers have been re- gravel zones are important as sources of water and 24 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

Bureau of Reclamation Bureau of Reclamation Test well 3A Test well 1 -----Northwest (B-5-1) 36bbb-1

~~------2 MILES------~

Boulders and gravel

Sand and gravel Sand and gravel 4500' 1------

Sand

Fine sand Sand and gravel

Sand Sand and gravel

:·:·.:·:.· .... . · .... :·.··.·· ~ 4400' 1------­ Sand with clay streaks Sand >w _J

<{ w (/) z <{ w Clay ~ w > Boulders and gravel 0 Ill <{ Sand w· 1'-'-~--c--,',.-~~~--;.j 0 Sand and gravel ::J t::: Sand f- 217'total depth

Sand and gravel

Sand

4200' 1------Sand and gravel

Sand

350'total depth

FIGURE 7.--Logs of two test wells on the Weber River flood plain. SUBSURFACE GEOLOGIC STUDIES 25 are here named the Delta and the Sunset aquifers in the river with hydrographs of wells in the Delta (pls. 5, 6). aquifer. The high-water stages in the river do not The difficulty encountered in tracing the lenticu­ correlate with high water levels in the well!s, al­ lar beds in the Weber Delta district is illustrated though pumping may obscure the effects of re­ by the logs of two wells near Woods Cross. Al­ charge. though Woods Cross is about 4 miles south of the LITHOFACIES MAPS district, deposits there are similar to those in the The general pattern of distribution of fine­ district. The two wells are 500 and 600 feet deep grained sediments (clay and silt) is shown on two and are less than half a mile apart. The cuttings maps prepared from data from drillers' logs. One collected from the· 500-foot well consisted largely map shows the ratio of clay and silt to coarser of gravel and sand with only a few layers of clay; materials down to 200 feet below the land sur­ whereas the 600-foot well penetrated a section face (pl. 2); the other shows these percentages from dominated by fine sand, silt, and clay. Beds can­ 200 feet to total depth of the wells (pl. 3). Areas not be correlated from one well to the other, even shown on the maps as being underlain by low per­ over so short a distance. centages of fine material are, therefore, underlain The logs of two test wells drilled for the Bureau by high percentages of sand and gravel. In terms of Reclamation on the flood plain of the Weber of grain size, then, the areas shown as low in fine­ River (fig. 7) show that in this area the material grained material are presumably more favorable is mostly coarse grained, much of it gravel, from for development of wells of high yield because of the land surface to a depth of at least 350 feet. greater permeability. Logs of wells drilled for Hill Air Force Base and These maps also suggest that deposition in river the Naval Supply Depot at Clearfield show that in channels was common during the history of the those areas similar sections of gravel are consid­ basin. For example, the coarse material in the erably deeper below the land surface. The differ­ area trending from Ogden Canyon toward Ogden ence in the altitude of the land surface, however, Bay Refuge was probably deposited by the ancient may account for the difference in depth, and the Ogden River. Other areas of relatively coarse ma­ gravel beds actually may be continuous from the terial appear on the lithofacies maps either as river flood plain to the Clearfield area. Such isolated rounded areas or as elongated areas that gravel could be part of an alluvial fan formed off are probably parts of old channels of the Weber the mouth of Weber Canyon during some period and Ogden Rivers. when the lake level was low. Because the fine ma­ A few sand layers may extend many tens or terials overlying the gravel are thought to be part perhaps hundreds of square miles, but because of of the Alpine Formation, the hypothetical alluvial their thinness, they do not appear on the lithofacies fan would be of early Alpine or pre-Alpine age. maps. The principal example of one of these The Delta aquifer is part of this inferred pre­ layers is a dark-gray to black sand, ranging in Alpine fan. thickness from about 12-18 inches, which has been Few subsurface data are available near the exposed along most of the Hooper Pilot Drain, dug mouth of Weber Canyon; therefore, the contours of by the Bureau of Reclamation in sees. 7, 8, and 18, the surface of the Delta aquifer in this area as T. 5 N., R. 2 W. Black sand is also reported at shown on plate 5 are largely interpretive. Certain depths ranging from about 8 to 20 feet in many information suggests that in this area an alterna­ parts of the Weber Delta district in holes that were tive interpretation is possible. Analysis of data jetted or augered during the drainage investiga­ obtained during aquifer tests on Bureau of Recla­ tion. The data suggest that the black sand may be mation wells 1 and 3A in sees. 36 and 27, T. 5 N., continuous northward beyond Plain City and south­ R. 1 W., suggests that an impermeable boundary ward to Farmington Bay; the east-west extent of is near each well in the subsurface. If this bound­ the sand is not known. ary exists, the gravel penetrated by the wells may LOGS OF TEST WELLS be wholly or partly fill in an old channel cut to an The Bureau of Reclamation has seven test wells unknown depth below the present land surface and (fig. 12) in the Weber Delta district, six of which the boundary may be a wall of the channel. A were drilled immediately before, during, or just separation, near the canyon mouth, of the gravel in after this study. Test well 2, (B-6-2)26ada-1, the present channel of the Weber River from the was drilled long before the start of the Weber Delta aquifer is indicated by a comparison of flow Basin Project. Test wells 1, 3A, 3B, 4A, 5A, and 26 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT 5B were drilled to depths as shown in the following in Hickey-Wilcox 1 and from 900 feet (the first tabulation. samples taken) to 2,060 feet in Hickey Rushforth Depth 1, gravel and sand predominate. The ostracodes Year Test well drilled (jeet) obtained from the interval between 606 and 1,305 1952 ______1, (B-5-1)36bbb-l______217 feet in Hickey-Rushforth 1 suggest (I. G. Sohn, 1953 ______3A, (B-5-1)27dcc-1______350 written commun., 1956) that a brackish-water 3B, (B-5-1)27dcc-2______115 1955 ______4A, (B-6-3)15dad-1 ______1,210 environment prevailed during deposition of those 5A, (B-5-2)16dcd-L ______978 sediments. Based on interpretation of electric 1956 ______5B, (B-5-2)16dcd-2 ______3,007 logs, aquifers will yield fresh water to depths of 1,300 feet near Bureau of Reclamation test well Samples were collected of the materials pene­ 5B, to about 1,100 feet near Wilcox 1, and to about trated by these wells; graphic logs of wells 1 and 800 feet near Rushforth 1. 3A are shown in figure 7, and graphic logs of wells The oil tests near Farmington probably are close 4A and 5B are shown on plate 4. Pumping tests enough to the Wasatch front so that they pene­ were made in wells 1, 2, 3A, and 3B (table 8). trated coarse detritus. The Bureau of Reclama­ Drilling for water in the Weber Delta district tion test wells near Roy ( 5B) and near West has been confined largely to . the zone less than a Warren ( 4A) are at distances of about 5 and 13 thousand feet below the land surface because in miles, respectively, from the front and are thus most places sufficient water has been readily ob­ farther removed from the source of coarse material. tained in that zone. Until 1956, accurate logs for GRAVITY SURVEY wells deeper than 1,000 feet were available for Gravity stations were established in most of the only three wells in the district. These were Bu­ Weber Delta district, and readings from the sta­ reau of Reclamation test well 4A, near West War­ tions were used to plot a simple Bouguer anomaly ren, and two oil tests (fig. 12), Jess Hickey Oil map (fig. 8). This map implies (D. R. Mabey, Co. Wilcox 1, (B-3-1)26dba, 3,000 feet deep and oral commun. 1956) that in general the bedrock Jess Hickey Oil Co. Rushforth 1, (B-3-1)36ddd, surface is in the shape of an elongated trough, the 2,060 feet deep, drilled near Farmington. deepest part of which is in the east-central part Generalized logs of these three wells and Bureau of T. 6 N., R. 2 W., about 3 miles north of the of Reclamation test well 5B show (pl. 4) that the Ogden Municipal Airport and about 5 miles west size of the materials at depth varies in the district. of the Wasatch front. The axis of the trough The log of test well 4A, near West Warren, shows a trends approximately N. 20° W., and, except succession of silt and clay beds, with sandy zones along the Wasatch front and at Little Mountain, intercalated throughout but decreasing in number the consolidated rocks forming the trough are not and thickness below about 800 feet. Examination exposed within the district. The gravity anomalies of the cuttings showed, furthermore, that the sand indicate that the unconsolidated or poorly consoli­ was commonly fine grained and mixed with silt. dated rock in the trough has a maximum thickness The total section penetrated was dominantly fine in on the order of 6,000-9,000 feet. texture and, therefore, probably not material from Details of the configuration of the bedrock sur­ which a water well could obtain a large yield. face cannot be determined from the gravity data. The materials penetrated by Bureau of Reclama­ The west side of the trough probably rises fairly tion test well 5B, near Roy, consisted of alternating evenly toward a north-south line through Little gravel, sand, and finer materials to a depth of Mountain. The configuration of the north and 1,626 feet. A gravel zone from 710-777 feet was south sides is less apparent, but the data suggest inferred to be the Delta aquifer. The section be­ that these bedrock surfaces rise less steeply. The low 1,625 feet did not contain gravel, and from east side may be a relatively smooth surface, or it about 950 feet to the bottom of the well at 3,007 may be a series of step faults; the Wasatch fault feet, clay and silt predominate. The only zones appears to form the boundary of the east side. The below 1,200 feet that might be aquifers were at depth of the unconsolidated material on the east 1,462-1,485, 1,552-1,580, and 1,619-1,626 feet. side of the trough is unknown but is on the order The oil tests near Farmington penetrated dif­ of a few thousand feet. The thickness of uncon­ ferent materials at depth than did test well 5B. solidated rock may be about 2,500-3,000 feet in the Samples were not collected from the upper parts northern, southern, and western parts of the area, of either oil test; but from about 800-3,000 feet where the bedrock is shallowest. SUBSURFACE GEOLOGIC STUDIES 27

R. 3 W. R. 2 W. R. 1 W. R. 1 E.

BOX ELDER CO /- WEBER co ___ _ T. 7 N. /

/ /

w ~

Ricer T. 6 N.

T. 5 N.

T. 4 N.

EXPLANATION

200---­ Kaysville Gravity contours 0 Contour interval, .5 m-ill-igals

Gravity• station

_Lj_...L.l.._Lj__Lj__Lj_...Ll....Ll...LL Farmington I T. 3 N. Boundary of consolidated rock 0

0 2 3 . 4 5 MILES

By D. R. Mabey, 1955

FIGURE 8.-8imple Bouguer anomaly map of the Weber Delta district. 28 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT The profile B-B' (fig. 9) shows the bedrock the Weber River. There appears to be a distinct surface from the Wasatch Range to Little Moun­ rise of the bedrock surface near Farmington Bay tain as determined from gravity and seismic data. and a less pronounced rise on the northern end of This profile is discussed in the next section together the profile. These rises correspond to the "bow" with the profiles determined only from seismic data. and "stern" of the "canoe-shaped" trough used in SHALLOW-REFLECTION SEISMIC SURVEY analogy to describe the surface. A shallow-reflection seismic survey was made by The approximate bedrock profile B-B' (fig. Dart Wantland and Robert Keummich, of the Bu­ 9) that extends from Little Mountain, where bed­ reau of Reclamation. John Roller, of the Geologi­ rock crops out, to the Wasatch Range shows that cal Survey, participated in the early stages of the bedrock surface descends to a maximum depth fieldwork. The following paragraphs summarize of about 6,300 feet below the assumed datum of unpublished data (Dart Wantland, written com­ 4,225 feet above sea level and then rises to the east mun., 1956) obtained during the seismic survey. to about 3,000 feet below the datum. This profile Some of the results have been reported by Mc­ is based on gravity and seismic data and is con­ Donald and Wantland (1960, p. 16-22). sistent with the concept of a horst of Precambrian The seismic data include 74 determinations of rock extending generally south- or southwestward the thickness of fill and 3 sets of measurements of from Little Mountain. seismic-wave velocities in drill holes. Depth deter­ Line C-C' (fig. 9 shows the approximate bed­ minations were made at intervals of lj2-Vh miles rock profile from near Hooper to the mouth of along 60 miles of traverses across the area. The Weber Canyon. Data from the westernmost shot traverses were tied to records of deep wells and to point indicate only about 2,800 feet of unconsoli­ bedrock at the outcrop on Little Mountain. Shot dated fill, and this apparent rise in the bedrock sur­ energies were sufficient to obtain reflections from face on the west may be related to the hypothetical bedrock to a depth of about 5,000 feet, but reflec­ horst mentioned in the preceding paragraph. A tions indicated bedrock only near Little Mountain. buried ridge in the bedrock may possibly extend In the rest of the area surveyed, therefore, bed­ along the entire western side of the Weber Delta rock was below 5,000 feet. district. Comparison with reflections from layers of sand In profile C-C', the gently sloping bedrock sur­ or clay at depths known from logs of deep wells face shown extending from the Wasatch Range permitted identification of extensions of 12 reflect­ westward nearly to the Bureau of Reclamation test ing layers in areas peripheral to the deep wells. well 5A at depths ranging from about 1,500 to At test well 4A, (B-6-3) 15dad-1, these layers were 3,000 feet, may not be accurately located. Assump­ in the interval from the surface to a depth of tion of smaller velocities was made because of the 1,210 feet. About 20 comparable reflections were high proportion of gravel, especially near the obtained from the undrilled interval between 1,210 surface, in the area. The gravity map (D. R. and 4,120 feet, implying that about 2,900 feet of Mabey, oral commun., 1956) does not show a simi­ alternating sand, silt, and clay is below the bottom lar bedrock profile. of the well. At test well 5A, (B-5-2) 16dcd-1, VOLUME OF UNCONSOLIDATED ROCK reflections from below the bottom of the well at The geophysical data can be used to estimate the 978 feet implied that alternating layers of uncon­ volume of unconsolidated and poorly consolidated solidated material exist to a depth of about 5,300 material in the Weber Delta district. The gravity feet. The correlation of individual strata was not values are assumed to vary in direct proportion to extended beyond 1 or 2 miles from individual deep the thickness of the underlying unconsolidated ma­ wells. terial. The area can be divided into segments of Interpretation of the geophysical data, especially equal thickness bounded by the gravity contours interpretation of the gravity survey, suggests that shown in figure 8, therefore, by assuming that each the bedrock surface dips eastward from outcrops increase of 5 milligals (the contour interval of the at Little Mountain and westward from outcrops map) represents an equal increase in thickness along the Wasatch front. The approximate bed­ of fill. Although the gravity values may not rock profile A-A' (fig. 9) implies that along a vary exactly in direct proportion to the thickness north-south line through the district unconsolidated of fill, the resulting data may be accurate enough material is thickest in an area extending roughly to permit their use in the estimate of thicknesses. from 1 mile south of well 5A to 2 miles north of Over the deepest point of the trough the gravity .,'­ " ~ Zl ~ @I~ ~ ~~(0 A """1))1 6000' I

2000'

SEA LEVEL

2000'

'- rtJ. ~ Profiles A-A' and C-C' based on q B B' seismic-reflection data; profile co 8000' 8000' r:n B-E' based on seismic and q 6000' 6000' gravity data. Assumed land­ surface datum is 4,225 feet above 4000' 4000' mean sea level ~ 2000' 2000' C':l t;rj 2 MILES SEA LEVEL SEA LEVEL G':l 2000' HORIZONTAL SCALE t;rj 4000' '"""~/'-"//V////, . /~~<:;/"<·';///. //,///// 2000' 0 4000' t"i 0 G':l 1-i C':l A 'z. ~. r:n ~-0~ 1-3 q North Ogden 0 \ t::! "1. 1-f Zl t;rj 21;.: rtJ. c f-11 Wasatch C' Ull Range., r 8000' "'"' j ~~· Test well 6000' I/ Tes~Awell 1 6000' 4000' 11 4000'

2000' 2000'

SEA LEVEL SEA LEVEL

2000' 2000'

4000' 4000'

Farmington 0 FARMINGTON BAY

FIGURE 9.-Sections showing approximate bedrock profiles and thickness of the overlying unconsolidated material in the Weber Delta district, Utah, inferred from seismic and gravity data.

t>,j ~ 30 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT value was -205 milligals, and the highest reading, great as the overlying sediments. The test bot­ -145 milligals, was recorded over what appears to tomed in these more resistant rocks at 2,009 feet, be a significant thickness of fill near Little Moun­ according to the electric log. Drill cuttings from tain. The gravity readings on and next to Little the oil test contained volcanic glass shards and Mountain were not used. Thus, there are 12 incre­ tuffaceous rock chips at depths ranging from about ments of 5 milligals between the highest and low­ 1,900 to 2,000 feet. Many of the rock chips re­ est values. sembled rock exposed in Ogden and Weber Canyons, The seismic profiles (fig. 9) indicate a maximum some miles upstream from the Wasatch front and thickness of fill of about 6,300 feet. From the outside the area mapped during this study. The greatest depth, the thickness of fill is assumed to formations that the well cuttings resemble consist decrease in 13 intervals (one being added to ac­ of pumiceous tuff, marl, and tuffaceous marl as­ count for the fill thickness at the station with the signed by various workers to the Salt Lake For­ -145 milligal reading), each having a thickness of mation. The oil test probably entered the Salt Lake about 6,300/13 or 480 feet (9 percent of 1 mile). Formation at 810 feet. Gravity data (fig. 8) are available over about The electric log for the other oil test near Farm­ 290 square miles of the Weber Delta district; the ington, (B-3-1)26dba, which is about 114 miles parts not covered are the Kaysville-Farmington farther west from the mountain front than test subdistrict and the northwestern part of the Ogden­ (B-3-1)36ddd, shows the same lithologic change at Plain City subdistrict. Using a planimeter, the 2,570 feet. This lithologic change, however, does area of each 5-milligal interval was measured in not appear in the electric log of the Bureau of Rec­ square miles. These areas were multiplied by the lamation test well 5B, (B-5-2) 15dcd-2, which bot­ thickness of fill obtained by using the value of 9 tomed at 3,007 feet but which is about 0.2 mile still percent of 1 mile of thickness per contour interval. farther west from the mountain front than oil The total volume of unconsolidated or poorly con­ test (B-3-1)26dba. The upper surface of the sup­ solidated material underlying that part of the dis­ posed Salt Lake Formation, therefore, dips sharply trict covered by the gravity survey is estimated to the west in the Weber Delta district. to be about 200 cubic miles. PLEISTOCENE(?) A maximum estimate of about 280 cubic miles The base of the Lake Bonneville Group at most of fill was obtained by using the maximum thick­ places probably is less than 200 feet below the land ness of 9,000 feet as determined from the gravity surface, and the unconsolidated and poorly consoli­ survey and applying the same procedure. A dated rocks between the Lake Bonneville Group and minimum estimate of 65 cubic miles was obtained the Salt Lake Formation, assuming that the Salt by calculating the volume of an inverted cone with Lake is present, are probably of late Pliocene and a height of 6,000 feet and a basal diameter of 15 early Pleistocene (pre-Lake Bonneville) age. The miles (the distance from Little Mountain to the exact position of the boundary between the Lake Wasatch front). The value of 200 cubic miles of Bonneville Group and the underlying older Pleisto­ fill probably approaches the true value as closely cene(?) strata is not known from available data. as available data permit. Conditions of deposition probably changed many FORMATION BOUNDARIES IN THE SUBSURFACE times during pre-Lake Bonneville Pliocene and PLIOCENE Pleistocene time. Lakes existed before Lake Bonne­ SALT LAKE FORMATION ville, and at least some of them were saline. Scour A basin as deep as that of the Weber Delta dis­ and fill occurred repeatedly as lake levels rose and trict can be reasonably assumed to have originated fell in response to changes in flow into the basin in Tertiary time. From available data, however, caused by changes in climate. These changing the Salt Lake Formation of Pliocene age is not conditions caused variations in the deposition of definitely known to occur in the subsurface of the sediments, but the details of these variations are basin, and the exact position of the subsurface not known. boundary between rocks of Tertiary and of Quater­ PLEISTOCENE nary age is not known. LAKE BONNEVILLE GROUP The electric log for the oil test (B-3-1)36ddd, Alpine Formation near Farmington, indicates a definite lithologic No criteria have been discovered by which the change at 810 feet, where the test penetrated rocks Alpine Formation can be recognized in the subsur­ that had electric resistivity two to three times as face. No guide fossils are known, and examination PALEONTOLOGY 31 of well logs has not revealed any persistent change north edge of Ogden, yielded cuttings that included in lithology that could be a formation boundary. a few specimens of Cytherissa cf. C. lacustris Based on evidence from Bureau of Reclamation from the surface to a depth of 50 feet. Because the test well 4A, (B-6-3) 15dad-1, near West Warren, test hole was jetted, the fossils recovered might all however, the base of the Alpine is inferred to be at have been washed from the wall of the hole in the a depth of about 200 feet. In that well, cuttings upper few feet below the surface. In any event, from the surface to a depth of 100 feet contain below 50 feet no further specimens of the Provo-age (pl. 4) an assemblage of ostracodes, consisting fossil were recovered. mostly of various speCies of Candona and of Lim­ An area of about 1 square mile, mostly in sec. nocyther·e, typically found in outcrops of the Alpine 14, T. 7 N., R. 2 W., near the tip of the Pleasant Formation. These ostracodes are forms common View salient, has yielded all the other specimens of to fresh-water lakes and ponds (I. G. Sohn, oral Cytherissa cf. C. lacustris (Sars) recovered from commun., 1954). In contrast, cuttings from 303 the subsurface. This fossil was found in samples feet below the land surface contained (I. G. Sohn, of clay collected from the surface to a depth of 15 written commun., 1956) species of ostracodes found feet in test holes drilled by power auger in a in brackish waters, which indicates a marked meadow north of Utah Hot Springs. Between 15 change in environment. As the zone from 100- feet and the bottom of an individual hole (generally 303 feet deep yielded few fossils, the exact position about 30 ft), however, specimens of this fossil were corresponding to the environmental change cannot not found. Four additional holes, the deepest of be fixed. The base of the Alpine Formation, there­ which was 100 feet, were jetted at intervals of fore, is assumed to be about 200 feet below the land roughly 1,000 feet along a line extending due west surface. of Utah Hot Springs. Samples from these holes Ostracodes found in cuttings from below 606 feet contained ostracodes which the senior author be­ in the oil test (B-3-1)36ddd also are reported by lieves to be Cytherissa cf. C. lacustris. These Sohn to be brackish-water types. Unfortunately, ostracodes were recovered from a depth of 40 feet cuttings were not collected from the upper 300 feet in the first hole, 1,000 feet west of the springs, and of that well, and ostracodes were not found from from depths of 50, 60, and 50 feet, respectively, at 300-606 feet. At that locality, therefore, the base three successive holes westward from the first hole. of the Alpine Formation can only be set somewhere The shells may have been washed from the upper higher than 606 feet below the land surface. part of the wall of the hole near the surface, how­ Study of cuttings from many wells and of fos­ ever, as discussed above. sils found in the Lake Bonneville and pre-Lake Bonneville deposits may eventually lead to the dis­ PALEONTOLOGY covery of criteria by which the base of the Alpine Invertebrate, vertebrate, and some plant fossils Formation can be identified. In this report, the were collected during this study, but only inver­ base of the Alpine Formation in the low-lying parts tebrate fossils were of any use in determining of the Weber Delta district is assumed to be at an stratigraphic relationships. Only one fossil, the altitude of about 4,000 feet. The altitude of the ostracode Cytherissa cf. C. lacustris (Sars), was con­ base of the Alpine Formation under the benchlands sidered a possible guide fossil. This ostracode is and foothills near the mountains is unknown. apparently restricted to the Provo Formation and

Provo Formation is useful in identifying that formation. The base of the Provo Formation may be at a INVERTEBRATE FOSSILS depth of about 50 feet in the Weber Delta district, Ostracodes were collected during this study by although this estimate is based on scanty data. the senior author and by I. G. Sohn, of the Geologi­ The only possible guide fossil in the Lake Bonne­ cal Survey, and the collections were studied by ville Group is the ostracode Cytherissa cf. C. lacus­ Sohn. In addition, fossils collected by C. B. Hunt tris ( Sars), which is apparently restricted to the in northern Utah Valley were studied. Sohn Provo Formation (see col. 2). This ostracode, how­ (written commun., 1954) stated that it was not ever, is absent from most well cuttings, including usually possible to determine sediment age within those samples obtained from shallow holes jetted the Pleistocene using ostracodes, because the time specifically to collect samples for geologic study, range of the ostracodes usually was from Miocene and it has been recognized in cuttings from only to Recent. However, he noted that the ostracode two localities. A test hole, (B-6-1)8dbb, near the Cytherissa cf. C. lacustris (Sars) seems to be re- 32 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT stricted to sediments of Provo age and thus may be he concluded that the sediments which contained useful in identifying Provo sediments. These ob­ the brackish-water ostracodes were probably de­ servations support the conclusions of Jones and posited in a saline lake. Marsell (1955, p. 103) who stated that the Mollusks are among the most common fossils in Cytherissa cf. C. lacustris occurs in the Provo de­ the Lake Bonneville Group. Most of the mollusk posits, but that it has not been observed in the specimens collected during this study were identi­ underlying Alpine Formation. fied by J. P. E. Morrison, of the Smithsonian Because Cytherissa cf. C. lacustris (Sars) has Institute, although D. W. Taylor, of the U.S. Geo­ a known range of Aftonian (pre-Kansan) or older logical Survey, identified specimens collected dur­ to Recent, some factor or combination of factors ing the latter part of the study. Many of the resulted in the ostracode being restricted to the mollusk specimens were also examined by E. J. Provo stage of Lake Bonneville. Roscoe, of the University of Utah. All the species Sohn (written commun., 1954) summarized the found in the Weber Delta district are still living in problem as follows: the region, and none was found to be useful in In order to accept Cythe-rissa cf. C. lacustris (Sars) as a either dating or differentiating Lake Bonneville recognition criterion for sediments of Provo age, a reason­ deposits. able explanation for its absence in Alpine and Recent sedi­ VERTEBRATE AND PLANT FOSSILS ments must be postulated. I believe that the following hypothesis, which has potential implications in the history Vertebrate fossils collected were identified dur­ of the Lake Bonneville group, is plausible. * * * Cytherissa ing the early part of the study by M. Jean Hough, lacustris is recorded as living in Asia, Europe, [and] North of the U.S. Geological Survey, and later by G. E. America, and as fossils in Interglacial of Europe and North Lewis, also of the Geological Survey, and by C. B. America including an unpublished record from the Pliocene or Quaternary of Alaska. * * * the absence of Cytherissa cf. Schultz and L. G. Tanner, of the University of C. lacustris in sediments of Alpine and Recent age cannot Nebraska. Hunt (Hunt and others, 1953, p. 21) be explained by a single factor, such as substrate or salin­ stated that few vertebrate remains have been found ity; it can, however, be explained by a combination of fac­ in the Lake Bonneville deposits. Vertebrate re­ tors that make up zoogeographic zones. mains were discovered at several places in the *** [Candona and Limnocythere], the genera common to the Weber Delta district, but they were either ques­ Alpine, Provo, and Recent sediments are present because tionably fossil or were of no use in determining they are tolerant to all kinds of environments. Cytherissa, the age of the deposits in which they were found. on the other hand, is restricted to the Palearctic zoogeogra­ In addition, much of the material could not be phic zone. It should be noted that Palearctic is a general term covering a considerable range of environments. identified. Apparently the eastern shore of Lake Bonneville was unfavorable for vertebrates; the ':'**the combination of factors that are favorable to the steep topography, for example, would not have presence of Cytherissa oscillated back and forth over the suited large plains animals. The northern, south­ area of Lake Bonneville, presumably connected in some man­ ner with the glacial oscillations. Conditions similar to Provo ern, and western shores of the lake, whose uncon­ time must have existed at some earlier pre-Alpine time, and solidated deposits are mostly unmapped, have it is possible that Cytherissa will be found in pre-Alpine gentler topography and may yield more vertebrate sediments. remains. Another group of ostracodes, although found in The late R. W. Brown, of the U.S. Geological only two sets of samples, was useful in interpret­ Survey, examined a few collections of plant frag­ ing conditions during deposition of the basin fill. ments, but he found none of the assemblages to be In the interval 610-615 feet in the Bureau of Recla­ distinctive of any age in the Pleistocene. mation test well 4A, (B-6-3) 15dad-1, an ostracode species of the Cyprideis group was found. This RADIOACTIVE AGE DETERMINATION group has a stratigraphic range of Miocene to Several samples were collected for carbon 14 Recent and lives in a brackish-water environment analysis. All the age determinations were made by (Sohn, written commun., 1955). In samples from Meyer Rubin, of the U.S. Geological Survey, and the oil test (B-3-1)36ddd, Sohn recognized ostra­ they have been published in the lists of radiocarbon codes characteristic of a brackish-water environ­ dates determined by the Geological Survey. None ment in the intervals 606-610, 770-775, 900-905, of the dates determined were particularly signifi­ 1,300-1,305, and 2,030-2,040 (written commun., cant to this study, although two determinations 1956). Sohn stated that these collections indicated were made of the age of the marl (unit 5) in the saline conditions but not a marine environment, and measured section in the SE~ sec. 21, T. 5 N., R. WATER RESOURCES 33 1 W. (p. 18). On the basis of field evidence, this each year. About 570,000 acre-feet comes into the marl is considered to be of Alpine age, but it had a area in the Weber and Ogden Rivers (including maximum radiocarbon age of 13,000 years. As water in a pipeline from Pine View Reservoir), in post-Provo time has been variously estimated to be mountain-front streams, and in pipelines from the from 10,000 to 25,000 years (Hunt and others, 1953, Ogden City wells in Ogden Valley; about 30,000 p. 43), the radiocarbon age of the Alpine marl is acre-feet comes into the area as ground-water too young. Perhaps the marl is younger than Al­ underflow from the mountain front; and about pine in age; or perhaps younger carbonaceous 350,000 acre-feet falls on the area below 5,000 feet material, such as plant roots, was included in the as direct precipitation. About 410,000 acre-feet of marl sample; or possibly ground water carried water leaves the area by the Weber River and younger material into the marl in some way. The smaller streams, by canals, drains, and sloughs, exact reason for the seemingly anomalous age is and by runoff of precipitation on the salt barrens; not known. 520,000 acre-feet is evaporated from land and wa­ ter surfaces or is transpired by plants; and about WATER RESOURCES 20,000 acre-feet is unaccounted for. Although the The following sections on the water resources of volume unaccounted for is only about 2 percent of the Weber Delta district emphasize ground water, the annual total, and within the limits of error of its recharge, availability, development, and chemi­ the data, there are compelling reasons (p. 56-57) cal quality. The conditions described are those for believing that a quantity of this order of mag­ prevailing during the period of study, 1953-56. nitude is discharged annually to Great Salt Lake Where available, information obtained before 1953 by underflow of ground w.ater. and after 1956 has been incorporated to achieve The elements of the water budget are summarized the benefits inherent in longer periods of record. in table 4 and are discussed in detail in the fol­ It must be emphasized that as development of lowing sections. the Bureau of Reclamation Weber Basin Project TABLE 4.-Water budget of the Weber Delta district, from an alti­ advances, the operation of additional water-storage tude of 5,000 feet to the shoreline of Great Salt Lake in 1952 facilities on the Weber River will introduce vari­ [Figures rounded to the nearest 5,000 acre-feet] Thousands Thousand ables that cannot be evaluated in detail in this of of Water entering area acre-feet Water leaving area acre-feet report. Virtually all the available streamflow in Weber River ______360 Weber River ______330 the Weber and Ogden Rivers presently in excess of Ogden River ______160 Canals ______10 existing rights will be utilized for project develop­ Mountain-front Drains and sloughs __ 20 streams ______35 Mountain-front ment. Further water development must be based Ogden City wells, stream discharge on ground water or imported water. piped into Weber into Great Salt Delta district from Lake ______15 The 3-year investigation in the Weber Delta dis­ Artesian Park ______15 Runoff from trict has served to show, in general, how far from Precipitation below precipitation on 5,000 ft ------350 salt barrens ______35 complete is knowledge of the hydrology of the Ground-water inflow I Evaporation and from mountain front 30 evapotranspiration: district. Many questions posed at the outset of the Underflow in Ogden Irrigated crops __ 170 study have been answered only tentatively, and new and Weber River Saltgrass pasture 160 stream channels ____ (1) Cattail areas ____ 60 problems have been discovered. ---- Dryland crops __ 45 Although the hydrology of the Weber Delta dis­ TotaL ______' 950 Salt barrens ____ 40 Water surfaces __ 25 trict has already been substantially altered by the Lawns, town- activities of man during the past century, basic sites, etc. _____ 20 ---- data are not available to analyze all these changes SubtotaL ____ 930 in detail. This is, then, a status report of areal Discharge unaccounted for; hydrology providing the general picture after a includes leakage to century of local development and before any effects Great Salt Lake ___ 20 --- of development and operation of the Weber Basin TotaL ______950 Project. 1 Negligible.

WATER BUDGET SURFACE WATER A water budget based on records and estimates WATER ENTERING THE AREA for the period 1928-47 indicates that about 950,000 The Weber River system, including the Ogden acre-feet enters and leaves the Weber Delta district River, contributes about 90 percent of the stream- 34 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT flow into the Weber Delta district. The. independ­ Bird Refuge (p. 68, 70) from the average annual ent streams draining the west slopes of the flow of the Weber River for the period 1928-47 Wasatch Range are the remaining sources of (calculated from records obtained at the Geological streamflow. Survey gaging station at Plain City). This An average annual flow of about 360,000 acre­ amount was subtracted because the Weber River feet of water entered the district from the Weber loses this water by evapotranspiration between the River during the period 1928 through 1947, and gaging station at Plain City (fig. 12) and the point about 160,000 acre-feet of water entered from where it leaves the project area. The computations the Ogden River during this same period (cal­ of discharge from the district in the Weber River culated from records obtained at Geological Survey are as follows: gaging stations on the Weber River near Gateway Acre-feet and on the Ogden River below Pine View Dam). Flow of Weber River at Plain City gage ______360,000 Less evapotranspiration: Streams draining the west slopes of the Wasatch From open-water surface: Range brought about 35,000 acre-feet annually 1,911 acres X 49.2 inches = 7,800 (table 5) into the area in Davis and Weber Coun­ From marsh area: ties during the period 1928 through 1947. 4,27 4 acres X 61.5 inches = 21,900 ______29,700 Available short-term records of Ogden City 330,300 were used to infer an average annual flow of 15,000 acre-feet of water into the area by pipeline Rounded to ______330,000 from the Ogden City wells in Artesian Park. Al­ though this is ground water in origin, it is obtained The Ogden-Brigham canal is the only canal in Ogden Valley, an intermontane basin about 10 carrying water out of the Weber Delta district. miles east of the Wasatch front. Aquifers in Og­ The flow of all other canals is accounted for within den Valley are not connected with those in the the district or is included in the flow of drains and Weber Delta district, and it appears reasonable sloughs, discussed below. to include this increment, by way of pipeline, with The water delivered to the area north of T. 7 N. surface-water inflow. through the Ogden-Brigham canal is based on The estimate of 350,000 acre-feet of water de­ shares or acre-feet subscribed by users of the irri­ rived annually from direct precipitation on the 400 gation water as follows: square mile area between altitude 5,000 feet and Users of irrigation Shares or acre-feet the 1952 shoreline of Great Salt Lake was cal­ water subscribed culated from a U.S. Weather Bureau isohyetal Box Elder Water Users' Assn ______1,234 map that showed average annual rainfall for the North Willard Irrigation Co ______300 period 1921-50. Planimetering the areas between Perry Irrigation Co ______484 Brigham City ______2,500 contours on the Weather Bureau map resulted in Willard Water Co ______600 the following figures: Three Mill Irrigation Co ______600 Weber-Box Elder Conservation District__ 5,300

Contour Average Total (rounded) ______10,000 interval I annual Factor Volume (inches of I Area precipitation sq mi to acres, of water precipitation) (sq mi) (inches) (inches to feet} (acre-feet) 12-16 ______190 14 640/12 141,500 The rounded total of 10,000 acre-feet is taken as 16-20 ______160 18 640/12 153,300 the annual amount of water leaving the district > 20 ______50 21 640/12 56,000 ------through canals. Total Water leaving the Weber Delta district in (rounded)_ 400 ------J_------350,000 drains and sloughs was measured by the Bureau of Reclamation during the period June 1952 to Although these figures are not adjusted to the December 1954 at gaging stations on the major period 1928-47, such adjustment probably would sloughs. Flows from minor drains that are not change them by only 1 or 2 percent. tributary to major sloughs are dissipated by evapo­ WATER LEAVING THE AREA transpiration and do not reach Great Salt Lake. The value of 330,000 acre-feet of water leaving The flow in the major sloughs during 1953 is the Weber Delta district annually by way of the estimated to be approximately equal to the mean Weber River was estimated by subtracting the for the period 1928-47; therefore, the following amount of evapotranspiration at the Ogden Bay slough records for 1953 were used to determine GROUND WATER 35 the total of 20,000 acre-feet that appears in the uncontrolled artesian wells ; and ( 3) by direct water budget: leakage into Great Salt Lake. Careful develop­ ment of the ground-water resources would lead to Slough records, in acre-feet, for 1953 recovery for beneficial use of some or most of this Howard Hooper Walker Dixie Total Slough Slough Slough Creek lost water.

January ------472 1,237 183 ' 1,006 2,898 OCCURRENCE FebruarY------787 624 105 270 1,786 March_ 617 448 88 245 1,398 Ground water in the Weber Delta district occurs ApriL __ 709 524 84 255 1,572 May __ _-_~~=====I under both artesian and nonartesian conditions in ------3,405 1,671 1 213 358 5,647 June __ _ ------2,480 1,503 ! 375 236 4,594 the gravel, sand, silt, and clay of the valley fill to ctober __ (1) i (1) (1) (1) (1) July to 0 I Novemb er ______613 395 I 68 175 1,251 known depths of 3,000 feet and possibly to depths December _____ -1 __57~~-- 38:_ ___2~·-- 21~ _ _2~44 of more than 6,000 feet. Large but unmeasured volumes of water also percolate through fractures Annual_ ____ ] 9,6541 6,791 I 1,189] 2,756 20,390 1 Assumed to be consumptively used before reaching Great Salt Lake. and joints in the rocks of the Wasatch Range. The water in the bedrock is important in recharging About 15,000 acre-feet annually reaches Great the valley fill, but it is not considered a part of Salt Lake through the lower reaches of mountain­ the ground-water reservoir in the district. The front stream channels. This water is spring run­ artesian reservoir of the valley fill contains the off and return flow below irrigation diversions. It bulk of the ground water. was measured or estimated in acre-feet as given Throughout the approximately 1,000 feet of below. valley fill in which ground water has already been developed, the ground-water reservoir is composed Kays Creek near mouth (3 forks) 1 ______3 , 000 Holmes Creek 2 ______1 , 300 of innumerable beds and lenses of sand, silt, and Haight Creek 3 ______1 , 600 clay and less abundant beds and pods of gravel Shepard Creek 4______700 intercalated. These materials are much the same Steed Creek 4______900 throughout the depth to which they have been Davis Creek 4 ______500 explored by drilling and throughout the thickness Farmington Creek 4 ______7 , 000 studied by means of the shallow-reflection seismic Total ______15,000 surveys described on page 28.

1 Based on continuous records obtained by the Bureau of Reclamation during The major artesian aquifers in the Weber Delta the period June 1952 to September 1954. 2 Based on continuous records obtained by the Bureau of Reclamation during district consist of relatively coarse sediments and the period June 1952 to January 1953 and daily readings during the period 1948-49. 3 Assumed as 45 percent of flow above all diversions. (Based on comparison to an extent are hydraulically interconnected. with other mountain-front streams.) 4 Based on daily readings below all diversions by the Bureau of Reclamation Measurements of water levels and pressures in during the period 1948-50. wells of different depths in the Weber Delta sub­ district (the subdistricts are described on p. 36) GROUND WATER indicate that at least two artesian aquifers which Ground water in the Weber Delta district occurs probably have only a slight hydraulic connection as shallow unconfined water, as local bodies of underlie most of the subdistrict at depths exceed­ perched water, and as confined water in artesian ing 200 feet. Locally, the subdistrict contains aquifers which are hydraulically connected to such other shallow aquifers, either artesian or water a degree that it is possible in some considerations table. The information available for other sub­ to deal with them as a single system. This report districts does not permit identifying the aquifers will be concerned principally with the artesian as well as has been possible in the Weber Delta aquifers, because the artesian aquifers of the dis­ subdistrict. The aquifers in the other subdis­ trict already have been developed to a significant tricts, however, probably correspond in depth to extent and because these aquifers contain by far those of the Weber Delta subdistrict. Maps of the greatest quantities of ground water suitable piezometric surfaces in the entire district, one for for future development. wells less than 400 feet deep (pl. 9) and the other The ground-water resources of the Weber Delta for wells from 400 to 700 feet deep (pl. 9), show district have not been fully developed. Large quan­ reasonable continuity of the piezometric surfaces. tities of confined ground water are lost principally Chemical-quality data suggest that water moves by three means: ( 1) by leakage into shallow aqui­ between aquifers through the confining layers of fers, resulting in evapotranspiration and seepage clay and silt. In many places in the district, the into drains; (2) by unused surface flow from water in shallower aquifers has a significantly 36 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT higher sodium-calcium ratio than water in deeper aries of the subdistrict (fig. 10) except one were aquifers at approximately the same locality. The drawn on the basis of chemical quality of water. writers believe that this circumstance reflects the The boundary with the Kaysville-Farmington sub­ exchange of cations between clay minerals and the district was drawn on the basis of a bedrock high water as the water passes through the confining known from logs of wells near Kaysville. The semipermeable clay beds in the course of its move­ subdistrict contains three smaller areas near Roy, ment upward from deep to shallow aquifers. Syracuse, and Layton in which the occurrence or the quality of the water is different from that of GROUND-WATER SUBDISTRICTS AND THEIR AQUIFERS the water of the subdistrict as a whole. These The Weber Delta district has been divided into areas are in the vicinity of the named towns, and six ground-water subdistricts: the Weber Delta, indefinite boundaries of the Roy and Syracuse Ogden-Plain City, North Ogden, West Warren, areas are shown in figure 14. Little Mountain, and Kaysville-Farmington sub­ districts (figs. 1, 10). The subdistrict boundaries Delta aquifer are based principally on the quality of water A thick and extensive deposit of interlayered yielded by the aquifers of the subdistricts. In some gravel, sand, and silt forms a fan-shaped body of the subdistricts, particularly in the Weber Delta extending westward in the subsurface from the subdistrict which is emphasized in this report, mouth of Weber Canyon. Some beds reportedly enough information is available to make prelimi­ also contain mixtures of materials such as "gravel nary identification of the aquifers. In others, such and sand" or "sandy silt." This deposit is the as the Ogden-Plain City subdistrict, the aquifers most developed aquifer and has the greatest poten­ have not been differentiated because the reasons tial for future development of all aquifers in the for the complex differences in chemical quality of Weber Delta district. It is herein named the the water have not been resolved. Delta aquifer. The boundaries of the subdistricts are not so The top of the Delta aquifer is about 500-700 sharp as is indicated in figures 1 and 10; areas on feet below the land surface at most places where it each side of most of the boundaries yield water has been identified in logs of wells, and the con­ of a quality gradational between the quality of figuration of the top is illustrated by a contour each of the adjacent subdistricts. These areas of rna p and profile (pl. 5). mixed water are indicated on the map showing The principal part of the aquifer is probably 50- chemical quality (fig. 14). 150 feet thick, but some wells have penetrated At many places in the discussion that follows, greater thicknesses without locating a lower bound­ chemical characteristics of water or chemical ary. The exact thickness of the aquifer remains changes in water, such as cation exchange, are unknown because most wells are drilled into the mentioned in general terms and without definition. aquifer only to the depth needed to produce water A more complete discussion of these characteristics in the quantity desired. Materials composing the and changes is included in the section on "Chemi­ Delta aquifer become progressively finer at increas­ cal quality" (p. 57). ing distances from the mountains, and the aqui­ fer loses identity near the line separating Tps. 2 WEBER DELTA SUBDISTRICT and 3 W. The Weber Delta subdistrict is the largest Many pumped wells of large yield obtain their ground-water subdistrict in the Weber Delta dis­ water from the Delta aquifer; for example, those trict and the one in which both present development at Hill Air Force Base, the municipal wells at and potential development of ground water are Sunset, and various of the larger wells near Clear­ greater than in the other subdistricts. The quality field. The results of aquifer tests suggest that of the water in this subdistrict is good, and the the permeability of the aquifer is high. The water water is suitable, without treatment, for most uses obtained from the Delta aquifer is of chemical char­ for which it is withdrawn. Many individuals acter suited to most uses for which it is pumped, maintain water softeners, however, and in a few although it is hard, containing much dissolved cal­ localities the water contains more iron than is de­ cium and magnesium. sirable. The subdistrict includes about 140 square The shape of the piezometric surface and chemi­ miles and is named for the huge fan-shaped delta cal analyses suggest that much of the recharge to built principally by the Weber River westward the Delta aquifer is from the Weber River; the rest from the mouth of Weber Canyon. All the bound- of the recharge is from surface and subsurface flow GROUND WATER 37 from the mountain front. The piezometric surface the vicinity of Roy and Syracuse, have been de­ shown on plate 9 is based mostly on measurements lineated largely from chemical quality-of-water in wells in the Delta aquifer. The configuration of data. (See p. 60.) In the Roy area the shallow the piezometric surface indicates movement of the aquifer probably has little hydraulic connection water in the aquifer radially outward from the with deeper aquifers, whereas in the Syracuse area mouth of Weber Canyon, generally northwestward the shallow and deeper aquifers are probably toward Riverdale, westward toward Hooper, and connected. southwestward toward Clearfield. Chemical data In the Roy area (fig. 14) a shallow aquifer yields (Smith, 1961) show that the water obtained water to wells 50-150 feet deep. Water from this from the Delta aquifer at Hill Air Force Base, at aquifer is more highly mineralized than water in Hinckley Field (Ogden City Airport), at Clearfield, the underlying deeper aquifers, and the piezometric and at other places where wells penetrate the surface in the shallow aquifer is higher than that aquifer is chemically similar to, but somewhat in the deep Delta aquifer. The differences in qual­ more highly mineralized than, water from the ity and differences in pressure in the two aquifers Weber River. In general, the percentage of so­ suggest that they are only slightly connected, if dium is greater in the ground water than in the at all. The shallow aquifer in the Roy area is river water, but not more so than can readily be relatively small in areal extent, and water dis­ explained by cation exchange which may occur charges from it through several seepage areas during percolation of water through the sediments. which are around the periphery of the area as The chloride content in both river and well water shown in figure 14. Normally, in deep aquifers in is in the same range of concentration. the unconsolidated deposits of the valleys west of Despite the evidence that the Weber River re­ the Wasatch Range in Utah, water is under charges the aquifer, there remains some doubt that higher static pressure than is the water in the the river is the main source of recharge because overlying shallow aquifers. In the Roy area, changes of stage in the river are not reflected by pumping from the deep Delta aquifer apparently corresponding changes in water levels in the has lowered the pressure in that aquifer, so that it aquifer. Heavy withdrawals of water from the is less than the pressure in the shallow aquifer. aquifer by pumping, however, may cause water­ In the Syracuse area (fig. 14) the chemical level fluctuations that mask any fluctuations pro­ quality of water from wells less than 250 feet deep duced by changes in flow of the river. might indicate that the shallow aquifer is not con­ Sunset aquifer nected to the deeper aquifers which yield water A shallower and less productive water-bearing that contains less dissolved minerals. However, the zone than the Delta aquifer is herein named the altitude of the piezometric surface is about the Sunset aquifer because the town of Sunset is near same in each of the water-bearing zones, which the center of the area underlain by the aquifer. indicates that the shallow and deep aquifers are Wells as shallow as 200 feet tap this zone, but in connected. It is suggested, therefore, that the dif­ most places the upper surface of the Sunset aquifer ference in chemical quality is due to cation ex­ is 250-400 feet below the land surface. The con­ change and an increase in total mineralization, figuration and profile of the upper surface of this both of which occur during upward leakage of the aquifer are shown on plate 6, and the configura­ water from the deeper to shallower aquifers. tion of the piezometric surface shown on plate 9 is OGDEN -PLAIN CITY SUBDISTRICT based largely on water-level measurements in wells The Ogden-Plain City subdistrict is north of the tapping the Sunset aquifer. Drillers' logs indicate Weber Delta subdistrict. The boundaries of the that the aquifer is from 50 to as much as 250 feet Ogden-Plain City subdistrict are shown in figures thick and consists largely of sand or mixtures of 1 and 10, but because of insufficient data, the gravel, sand, and silt or of sand and silt. The northern boundary is not defined. Large yields Sunset aquifer is less permeable than the Delta can be obtained from wells in parts of the sub­ aquifer, and no wells of large yield are known to district, but in places the water contains consid­ obtain water from the Sunset aquifer. Water in erable sodium and chloride in solution. Individual the Sunset aquifer is similar in chemical quality aquifers in this subdistrict have not been identified to water in the Delta aquifer. because it is not known whether the complex pat­ Shallow aquifers tern of occurrence of water of various chemical Shallow aquifers, which supply water to wells in types is caused by many discontinuous aquifers or 38 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT water of different chemical type in a few continu­ widespread drilling. Individual aquifers have not ous aquifers. Wells in the subdistrict are from been identified, but most wells are about 190-325 50 to 900 feet deep, but most wells are from 250 feet deep. to 600 feet deep. KAYSVILLE-FARMINGTON SUBDISTRICT The Kaysville-Farmington subdistrict is south of NORTH OGDEN SUBDISTRICT the Weber Delta subdistrict (figs. 1, 10). Wells The boundaries of the North Ogden subdistrict, in the Kaysville-Farmington subdistrict near the which is north of the Ogden-Plain City subdistrict, vVasatch Range generally have small yields, but are shown in figures 1 and 10. Because of in­ the water is of good chemical quality. Farther sufficient data, the northern boundary of the sub­ westward, the sodium content is increased by district is not defined. cation exchange, and the water becomes less suit­ The artesian aquifer in the North Ogden sub­ able for irrigation. district is at relatively shallow depth near North The aquifers in the subdistrict are separated Ogden, but it apparently extends southwestward from the aquifers of the Weber Delta subdistrict beneath a thick cover of clay. Although the aqui­ by a bedrock high which is encountered in wells fer consists of coarse sand and gravel, the wells a few hundred feet deep in Kaysville. South of tapping it have relatively small yields. Excep­ Kaysville, pressure heads are generally small. In tionally high artesian heads in the aquifer permit the area extending from 11/ miles north to 3 miles the water to rise in wells to levels above 4,300 2 south of Farmington, and from Farmington west­ feet, the approximate maximum altitude at which ward to the lake, the distance above land surface to wells flow in other subdistricts. The aquifer which water from wells will rise decreases toward yields water of excellent chemical quality. The the west. This unusual pressure condition, in water contains less dissolved minerals than does which the hydraulic gradient is steeper than the water from artesian aquifers in nearby areas. The topographic slope, is probably caused by the low differences in pressure and quality indicate that the permeability of the aquifers and the flatness of the aquifer in this subdistrict is at least partly sepa­ topography. rated from the aquifers in adjacent subdistricts. RECHARGE Water in the overlying water-table aquifer is SOURCE OF RECHARGE very hard and generally requires softening for The ultimate source of all ground water in the domestic use. Weber Delta district is precipitation which falls

WEST WARREN SUBDISTRICT mostly in the form of snow on the drainage basin in varying quantities from year to year. Some of The West Warren subdistrict lies west of the Ogden-Plain City subdistrict and northwest of the runoff resulting from this precipitation con­ the Weber Delta subdistrict. The boundaries of tributes the principal recharge to the ground­ the West Warren subdistrict are shown in figures water reservoir, either directly from the streams 1 and 10, but because of insufficient data, the north­ that drain the mountains, or indirectly as seepage western boundary is not defined. The ground from canals and irrigation. On the benchlands along the mountain front, a part of the precipita­ water in the subdistrict is satisfactory for culinary use, but it generally is not satisfactory for irriga­ tion percolates directly to the aquifers, after tion because it is of sodium bicarbonate type. evapotranspiration losses have occurred and soil­ Individual aquifers have not been identified in this moisture deficiencies have been satisfied. Direct precipitation and irrigation on the flatlands west subdistrict, but most wells are 300-600 feet deep. of the mountain front contribute little or no re­ LITTLE MOUNTAIN SUBDISTRICT charge to the deep aquifers, but they probably The Little Mountain subdistrict includes the area contribute to recharge of the shallow aquifers. from Little Mountain to Hooper Hot Springs and PRINCIPAL RECHARGE AREA much of the Ogden Bay Bird Refuge (figs. 1, 10). The zone most favorable for recharge to the The ground water in this subdistrict contains con­ artesian aquifers in the Weber Delta district ex­ siderable sodium chloride and probably is unsatis­ tends, at the most, only about llh miles westward factory for most common purposes. Few wells are from the mountain front. This zone consists bas­ known to be in the subdistrict, partly because it ically of two parts : the channel of the Weber River consists mostly of mudflats and saltgrass pasture­ from the mouth of Weber Canyon to a point 1112 land, but also, perhaps, because the quality of miles to the west and a belt of gravel and sand, water encountered by wells has not encouraged ranging in width from a few feet to a few thousand GROUND WATER 39 feet, that lies just west of the mountain front The Wasatch fault zone extends along the front throughout most of the district (fig. 10). The of the Wasatch Range, and is marked by many recharge zone readily absorbs underflow from the cross faults and branch faults in a strip about 1 mountain front, part of the runoff from the major mile wide. In many places, late Pleistocene and and lesser streams, and some moisture directly Recent movement of these faults has cut the fine­ from precipitation. Other zones, farther from the grained Alpine sediments, and some recharge may mountain front, accept direct infiltration from pre­ percolate to the deeper aquifers along these faults cipitation and from irrigation, although probably (Dennis, 1952, p. 9). less readily than the zones closer to the mountains. SUMMARY OF RECHARGE The belt of gravel and sand close to the moun­ The calculated mean annual recharge to the tain front is formed of high-level bench gravels aquifers in the Weber Delta district is 70,000 acre­ occupying terraces near the 4,800-foot (Provo) and feet of water. The various sources of recharge 5,200-foot (Bonneville) shorelines and occurring at and the estimated volumes of recharge are as points between these two shorelines. In places follows: where the present canyons cut deeply through the Surface streams: Acre-feet terraces, it is apparent that in some areas clay and Weber River near canyon mouth______16,000 silt extend nearly to the hard rock of the Wasatch Ogden River near canyon mouth ______2,000 Range. In others, however, beds of gravel extend Mountain-front streams______3, 000 well up toward, and probably in many places make Mountain-front subsurface flow ______30,000 Direct infiltration: actual contact with, the rock of the Wasatch Range. Precipitation______10 , 000 A gravel pit in North Ogden reveals some of Irrigation seepage and canal losses to benchlands the relationships that must exist at various places and flood plains______6, 000 throughout the district. This pit is in the SW!4 SW14 sec. 27, T. 7 N., R. 1 W., where, at various Total ~ounded) ______70,000 stages of the history of the Bonneville Basin, sedi­ RECHARGE FROM SURFACE STREAMS ments might easily have been derived from North WEBER RIVER Ogden and Coldwater Canyons and the next canyon The Weber River is the most important localized south. The pattern of crossbedding in the sand source of recharge to the aquifers of the Weber and gravel exposed in the pit suggests that at vari­ Delta district. When the Weber Basin Project ous times each canyon contributed material to the reaches full development, however, only flood flows sediments now displayed in the walls of the pit. will reach the most favorable recharge areas, and The gravel is inferred to be part of an old alluvial therefore, the recharge from this source may be fan or near-shore delta formed by discharge of diminished. sediments jointly from North Ogden and Cold­ A series of measurements of seepage losses was water Canyons. The north wall of the pit is made in the channel of the Weber River down­ formed entirely of clay and silt of the Alpine stream from the point where the river emerges Formation. The clay and silt on the east wall of from the mountains. These measurements show the pit form a tongue projecting above and cover­ that in the first 1112 miles the loss of flow in the ing the sand and gravel of the older deposit. Evi­ river ranges from 0 to as much as 18 percent of the dently in this area, deposits of highly permeable total discharge. The mean value calculated for sand and gravel were laid down adjacent to the the loss is about 7 percent of the discharge. Based mountain front and for some distance into the on this calculation, estimates were made of infil­ basin. When lake levels again rose in the basin, tration for the year 1934, one of very low flow, the flanks and top of the gravels were enclosed in and for the year 1952, one of near maximum flow. silt and clay of the Alpine Formation. Whether These estimates show infiltration in the first 1112 the enclosed sand and gravel represent an earlier miles west of the mouth of Weber Canyon of 9,000 stage of Alpine deposition or whether they are acre-feet in 1934 and 100,000 acre-feet in 1952. pre-Alpine in age is not know. Comparable condi­ Inflow-outflow studies for the reach between the tions probably occur at many points and at various Geological Survey gaging stations at Gateway and levels in the subsurface along the mountain front Ogden on the Weber River suggest a mean annual where streams have built deposits largely of recharge of about 20,000 acre-feet for the period coarse-grained permeable material which were 1951-58. For the reference period 1928-47, the later enclosed by finer grained lake sediments. adjusted annual recharge was 16,000 acre-feet. Of 40 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

R. 3 W. R. 2 W. R. 1 W R. 1 E

BOX ELDER CO z /--wEBER C-0-- ::; T. 7 N. / 0 0::: / w I ~ Plain City 0

w z ~ ')::' <{ ....J ')::' T. 6 N. -\ () "!.

f- ....J <{ (/)

T. 5 N.

EXPLANATION ~ Gravel and sand Absorbs water readily T. 4 N. ·.·. ···l ~·: ...... ·:·J Gravel and sand probably under­ lain by fine-grained sediments Ability to transmit water to aquifers 1:s not known

Cambrian limestone T. 3 N Absorbs water readily

Precambrian metamorphic rocks 0 2 4 5 MILES and Cambrian quartzite or lime­ stone Probably absorbs water in subsur- Contact face fractures along the mountain front and transmits it to aqui­ Subdistrict boundary fers in the unconsolidated val­ ley jill

FIGURE 10.-Map of ground-water subdistricts in the Weber Delta district showing probable areas of ground-water recharge. GROUND WATER 41 this, probably about 14,000 acre-feet infiltrates in 5). The perennial flow of most of these streams the 11/2 mile stretch just west of the mouth of is conducted in pipes or canals across the highly Weber Canyon. permeable recharge zone adjacent to the moun­ The piezometric-surface maps (pis. 9, 10) show tains, but some of the high spring runoff and water a marked pressure bulge westward in Tps. 4 and from flash floods in the summer bypasses the diver­ 5 N. that reflects recharge from the Weber River. sions and enters the ground in the recharge areas. The isopiestic lines bow outward away from the Probably about 10 percent of the total runoff, or canyon mouth more than do the land-surface about 3,000 acre-feet per year, actually recharges contours, indicating that a large volume of water the aquifers. is being added to the aquifers from the vicinity of TABLE 5.-Estimated annual runoff from mountain-front streams, the mouth of Weber Canyon and southward. T. 3 N. to T. 7 N., inclusive In the principal recharge area, just west of the Stream Runoff Stream Runoff (acre-feet) Wasatch Range, the flood plain of the Weber River (acre-feet) Rice ______1600 North Fork of Holmes __ I 1,800 Holmes ______is underlain by coarse gravel and sand, and the North Ogden ______I 1,000 3 2,800 Coldwater ______11,000 Haight______13,500 Shepard ______water table in this area, on the average, is about Taylor ______2 500 11,900 WaterfalL ______, 2 500 Farmington ______3 10,000 Steed ______160 feet below the land surface. Recharge is Strongs ______2 500 12,000 Burch ______12,000 Davis ______11,200 rapid because the sediments have high permeabil­ Spring ______1 300 Others ______2 500 North Kays ______11,400 TotaL ______ity and are hydraulically connected with aquifers Middle Kays ______I 1,400 34,900 South Kays ______1 1,400 Total rounded __ _ 35,000 of high permeability. During the summer of 1955, Snow ______1 600 I Estimated from spot measurement. a trench about 15 feet deep was dug across the 2 Estimated. channel of the Weber River to permit installation 3 Calculated from stream-gage records. of a pipeline, part of the Weber Aqueduct of the MOUNTAIN-FRONT SUBSURFACE RECHARGE Bureau of Reclamation. The trench showed that A large quantity of water, admittedly difficult at low-water stages in the river, recharge occurs to estimate, recharges the aquifers in the Weber vertically downward. The gravels of the flood Delta district by subsurface flow from the bedrock plain were entirely dry to maximum depth of the and overlying surficial material of the Wasatch trench, except just below the wetted part of the Range. The presence of subsurface flow is sup­ river channel. ported by the configuration of the piezometric Near the west border of the recharge area, a surface of the aquifers in the district, by chemical­ few shallow wells ranging in depth from 60 to 115 quality data, by evidence from radon studies, and feet show the presence of a perched water table by measurements of water in Gateway Tunnel. that slopes eastward contrary to the slope of the The total amount available for recharge by land (pl. 9). Shallow ground water in that part of subsurface flow is estimated in the following man­ the river flood plain moves eastward above a clay ner to be about 30,000 acre-feet (table 6). The layer that becomes progressively thinner to the volume of precipitation over the Wasatch Range, east and wedges to disappearance about 1112 miles from an altitude of 5,000 feet to the crest of that west of the Wasatch front. There the water spills part of the range just east of the Weber Delta over the clay lip adding to the recharge of the district (excluding the areas which drain directly deeper aquifers. into the Weber and Ogden Canyons) is calculated OGDEN RIVER by increments of elevation from data of the U.S. The annual recharge from the Ogden River is Weather Bureau. The loss by evapotranspiration much less than that from the Weber River. Seep­ is also calculated by increments of elevation, using age measurements made in a reach of about 1 mile data from U.S. Forest Service studies on the water­ just west of the mouth of Ogden Canyon suggest a shed. The estimated evapotranspiration and the net loss of flow of about 3 cfs (cubic feet per sec­ runoff from mountain-front streams are deducted, ond) at the times of measurement. Using the loss and the remainder, 30,000 acre-feet, is the cal­ rate of 3 cfs, an arbitrary estimate of 2,000 acre­ culated volume of average annual subsurface re­ feet per year is calculated as the annual recharge charge along the mountain front. from the Ogden River. This is probably a mini­ EVIDENCE FROM THE PIEZOMETRIC SURFACE AND FROM mum value. CHEMICAL-QUALITY DATA MOUNTAIN -FRONT STREAMS The slope of the piezometric surface away from The estimate of runoff from mountain-front the mountain front toward Great Salt Lake indi­ streams is about 35,000 acre-feet per year (table cates that the mountain front is a linear source of 42 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

TABLE 6.-Calculation of volumes of water available for recharge 26aaa and the Weber River in table 9.) This water by subsurface flow from the mountain front, T. 3 N. to T. 7 N., inclusive is chemically similar to water from mountain springs and from Gateway Tunnel (analyses for MOUNTAIN-FRONT PRECIPITATION springs (B-5-1)25d and (B-7-1)22abc and Gate­ 1 Amount of precipitation I 1 I ------• Area between way Tunnel in table 9), and, therefore, presumably October to April I Annual average I isohyetal lines is derived from recharge along the mountain front. ----~------·~- along mountain I Annual volume

1 Range Average . Inches I Feet front of precipitation Further evidence that the mountain front provides (inches) (inches) . · __ (acres) (acre-feet)

I 12-16 14 21.0 1.75 5,700 10,000 subsurface recharge is presented in the section on

16-20 18 26.0 2.17 1 12,000 26,000 "Chemical quality." 1 2o-24 22 , 31 . o 2 . ss 1 n ,ooo 28,000 24-28 26 36.o 3.oo I 14,ooo 42,000 EVIDENCE FROM WEBER CANYON RADON STUDIES 28-32 30 41 . 0 3 . 42 6 '900 24,000 Radon studies made on a reach of the Weber 1 J 32 32 1 43 . 5 3 . 62 3 900 14,000 River that showed gains in flow indicated that the Totals (rounded) ______53,000 144,000 source of the water was bedrock rather than dis- Adjustment of total volume to 1928-47 charge from bank storage. Seepage measurements ---=pc_e_ri_o_d_: _1_44-'-,_0_0_0~X~9_6--=p_e_rc_e_n_L______-_-_-_-_- __- -_-_-_-_- ~~-13_8__c•_o_oo were made on a reach of the Weber River between

ESTIMATED EVAPOTRANSPIRATION 2 a powerplant near the mouth of Weber Canyon and Mountain front, 5,000 feet to crest a diversion dam 13,4 miles upstream. At low-water Annual stages these measurements showed that the river Elevation rate zones Area I Annual volume consistently gains about 5 cfs in the reach, mostly (feet) Inches Feet I (acres) (acre-feet) I from the south side in the lower half a mile of the 5,000-6,000 _____ 20.0 1.67 14,000 23,000 6,000-7,000 _____ 17.5 1.46 18,000 26,000 reach. 7,000-8,000 _____ 15.0 1.25 14,000 17,500 In an attempt to determine the source of this 8,000-9,000 _____ 12.5 1.04 4,500 4,700 water, A. S. Rogers, of the Geological Survey, made 9,000-10,000 ____ 1 10.0 .83 I 2,400 2,000 ~------a study of the radon content of the water; his work Totals (rounded) ______, 53,000 73,000 (Rogers, 1958, p. 205-208) indicated that the bulk Computed annual ground-water inflow (recharge), in feet, along of the inflow in the reach of the Weber River was the mountain front: Mountain-front precipitation (above) ______138,000 derived from bedrock sources and not from bank Less evapotranspiration (above) 73,000 storage in alluvial materials that are present at Less mountain-front streams (table 8) 35,000 some places along the river. The rocks of the 108,000 Wasatch Range are evidently contributing an ap­ Net ground-water inflow______30,000 preciable volume of water to the Weber River; the

I October-April data from the U.S. Weather Bureau, Annual data converted rocks of the range, therefore, are assumed to be from October-April data using Weather Bureau correction factors. 2 U.S. Forest Service unpublished data. capable of yielding water to aquifers along the west front of the range. recharge (pl. 9). This is particularly evident in EVIDENCE FROM GATEWAY TUNNEL the southern part of the area extending about from Further knowledge of the water-bearing prop­ Kaysville to Bountiful (pl. 9). During spring erties of the bedrock in the Wasatch Range was runoff, large volumes of water enter the rock of gained during the drilling of the Gateway Tunnel. the mountain mass itself through fissures, joints, This tunnel, shown in figure 12, is one of the facil­ and other openings. In addition, water enters the ities of the Weber Basin Project. It extends 3.3 soil on the mountain front, and in most years miles from the mouth of Weber Canyon upstream enough water is available to satisfy the field through metamorphic rocks, thus penetrating a capacity of the soil, so that some water can perco­ main ridge of the Wasatch Range. A considerable late down to the weathered-rock mantle. This flow of water was encountered about 1,100 feet water within and on top of the rock probably moves from the west portal. During the rest of the gradually downward and finds its way into the tunneling operations additional flows of water were sand and gravel aquifers along the mountain front. encountered at various points. In July 1953, a In a 3- to 4-mile-wide band parallel to the 6-inch Parshall flume was installed in a ditch that southern border of the Weber Delta subdistrict, drained water from the west portal of the tunnel. through the town of Layton, water from wells has Except for minor interruptions, the flume was smaller concentrations of dissolved solids and chlo­ operated until September 1954. Records obtained ride than does water from the Weber River. (See from this flume do not show all water yielded by analyses for wells (B-4-1)20cbb-1 and (B-4-2) the tunnel because it was necessary to pump water GROUND WATER 43 from the tunnel at various times during the drill­ infiltrates to the ground-water reservoir, the ing operation. A hydograph (pl. 7) based on the amount of recharge is (adding factors to change flume records and measurements made after the inches to feet and square miles to acres): flume was removed shows, however, that during 0.25x 14x 1/12x60x 640=11,200 acre-feet. the period July 1953 to March 1955 the tunnel dis­ An estimate of the amount of recharge from charged from about 180 to 450 gpm. A peak flow direct precipitation on the area between 4,300 feet of 580 gpm was recorded, but it was not long and the mountain front, therefore, is about 10,000 sustained. acre-feet per year. The hydograph on plate 7 is definitely not a An unknown, but probably large amount, of the depletion curve such as would be expected if the Weber Delta district has reasonably permeable tunnel derived water only from storage in rock materials at the surface, but it is underlain at fissures. Rather, the hydrograph suggests that depth by clay that is less permeable than the sur­ the fissures receive recharge from snowmelt which face material. Some of the clay, being only would probably find its way through fissures in slightly permeable, supports perched water bodies; the rock to the valley aquifers if it were not inter­ but other clay layers, because of internal struc­ cepted by the tunnel. A spring below the tunnel tural arrangement, are sufficiently permeable to diminished in flow during the drilling of the tunnel, permit water to pass through them and recharge thus suggesting that some of the water encoun­ the underlying ground-water body. tered in the tunnel may have normally discharged Laboratory tests of vertical permeability were from this spring. made on four undisturbed clay samples which RECHARGE FROM PRECIPITATION, IRRIGATION, AND CANALS were obtained from depths of 5-9 feet in the Bu­ Direct infiltration of precipitation, seepage from reau of Reclamation B-5 drain area in sec. 16, T. irrigated areas, and seepage from canals supply 4 N., R. 2 W. The vertical permeabilities deter­ recharge to the artesian aquifers. Much of the mined after 271 hours were as follows: water from these sources evaporates or is trans­ Sample Permeability (inches per hour) pired by vegetation, but about 16,000 acre-feet (25 1 ______0.002 percent of the total available) might recharge the 2------.001 ground-water aquifers in areas above an altitude 3------.000 of 4,300 feet. Below 4,300 feet this water could 4 ______.000 penetrate to the water table because artesian only Average ______.00075 pressures would prevent recharge to the arte­ sian aquifers. It can be assumed that in the area of 60 square

DIRECT INFILTRATION OF PRECIPITATION miles which is underlain by reasonably permeable Some of the precipitation that falls on the more materials, these materials, in turn, are underlain permeable surfaces of the Weber Delta district by clay whose vertical permeability may be about percolates downward toward the aquifers. No 0.00075 inch per hour. This area then would be attempt was made to measure the actual recharge capable of accepting recharge as follows: from precipitation in the large area of the dis­ 0.00075 in per hr=0.0015 ft per day =0.55 ft per yr. trict. Instead, it is estimated that 25 percent of On this basis, therefore, an area of 60 square miles, the precipitation reaches the ground-water body. or about 38,000 acres, could accept about 20,000 This estimate is probably reasonable, because it acre-feet of recharge per year. As there is very is comparable to an estimate based on laboratory little runoff from this area and the clay may accept determinations of the permeability of samples of recharge at this rate, the original estimate of surficial materials collected in the district. about 10,000 acre-feet of recharge per year from The area between an altitude of 4,300 feet and precipitation is reasonable. the mountain front and between the Box Elder SEEPAGE FROM IRRIGATED AREAS AND CANALS County line and the north boundary ofT. 2 N. that The 60 square miles that are underlain by rea­ is underlain by reasonably permeable materials is sonably permeable materials include about 4,600 about 60 square miles (measured by planimeter on acres of irrigated land on which the annual diver­ fig. 10). The October-April precipitation which is sion of water is about 31j2 acre-feet per acre. If available for recharge in that area ranges between 25 percent of the water diverted infiltrates to the 12 and 16 inches, with an average of about 14 ground-water reservoir, then the amount of re­ inches (fig. 2). If 25 percent of this precipitation charge from this source is about 4,000 acre-feet. 44 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

Water is diverted from the Weber River in un­ 4400 lined irrigation canals which cross the principal recharge area of the Weber Delta district near the I I I mountains. (See p. 38.) These canals divert about Recharge experiment 2 7,200 acre-feet per year, and they undoubtedly lose 4390 water to the recharge area. The loss from the canals is estimated to be 25 percent of the water \ ...J diverted; thus, the recharge from these unlined w > 4380 canals is about 2,000 acre-feet per year. w ...J Differences in the quality of the water (p. 60) <{ w in the deep and shallow artesian aquifers in the (f) I Roy area suggest that the shallow aquifers are z 4370 <{ eRechargel experi~ent I recharged by infiltration of excess irrigation wa­ w ~v ~ ~ ter applied to the benchlands east of Roy. The w > exact amount of this recharge, however, is not 0 \ Recharge experiment 3\ a:J 4360 known. <{ \ ARTIFICIAL RECHARGE EXPERIMENTS f-w w The flood plain of the Weber River, near the LL. mouth of Weber Canyon, is underlain by permeable z 4350 1\ ~ - \ sand and gravel to at least 217 feet. This is the _j depth of Bureau of Reclamation test well 1, (B-5-1) w >w I 36bbb-1, which was drilled in December 1952 to be ...J 4340 ~ J 0::: used as an observation well during artificial re­ w f- charge experiments. In an earlier investigation, <{ \ Dennis ( 1952) considered the mouth of Weber ~ \_1/ Canyon to be the area where recharge is greatest 4330 and concluded that artificial recharge should be tried there. c ~ c ~ c ~ ro :l ro :l ro :l In February and March 1953, recharge experi­ --, --, --, --, --, --, I I I I I I I I I I I I I I I I I I I I I I I I ""I I I I I ments were made near the mouth of Weber Canyon 4320 1953 1954 1955 by running surplus flows of the Weber River into a pit having an area of 31,4 acres and a depth of 30 FIGURE 11.-Hydrograph of Bureau of Reclamation test well 1, feet. The two experiments lasted a total of 7 (B-5-1) 36bbb-1, January 1953 to December 1955, showing weeks, and about 2,170 acre-feet of water infil­ effects of artificial recharge. trated into the pit, equivalent to a continuous flow of 7 cfs per acre. The recharge affected the The confining layer over the artesian aquifer in water level in test well 1 of the Bureau of Recla­ this area consists of a clay layer that thins toward mation 3 days after the experiment began, and the the east. The Bureau of Reclamation test well 3A, water level rose 34 feet during the experiment (B-5-1)27dcc-1, was drilled in November 1953 (fig. 11). Test well 1 is a quarter of a mile west about 11;2 miles west of test well 1. Test well 3A, of the recharge pit; therefore, under unconfined which is 350 feet deep, was drilled to act as an conditions, the velocity of the water was about 440 observation well in recording the pressure wave feet per day. from the recharge pit and to determine the thick­ The available evidence is inconclusive, but ap­ ness of the confining clay layer. The confining parently the pressure wave from the recharge layer was found to be 7 4 feet thick and to lie experiments affected observation wells to a distance between 110 and 184 feet below the land surface. of about 6 miles. No observation wells were avail­ The areal extent of the clay layer is not known able west of the Bureau of Reclamation test well 1 and, therefore, the eastern edge of artesian condi­ for a distance of about 3 miles; but, in observation tions is unknown. wells 3-6 miles from the recharge pit, water levels A third recharge experiment was attempted from rose nearly simultaneously about 1 month after the December 1954 to March 1955. Exceptionally cold experiment began. This probably was caused by weather froze the recorder floats in the observation the recharge water entering an artesian aquifer. wells and froze the water in the delivery canal. GROUND WATER 45 Later, high-stage turbid waters interfered with penetration) in the heart of the Weber Delta dis­ recharge by depositing silt in the pit. Although trict, the sediments are mostly fine grained; thus, the experiment failed to produce continuous rec­ yields from aquifers below 1,300 feet probably ords, the effect of recharge was recorded at both would be small. wells, reaching test well 1 in 5 days and test well Large areas in the Ogden-Plain City subdis­ 3A in 13 days. A fourth recharge experiment trict are underlain by fine-grained sediments, and was conducted from November 1957 to February yields from many wells are small. Thus, despite 1958, but figure 11 does not include this period the large volume of valley fill in the Weber Delta and therefore does not show the effects of this district and the presumed large total volume of experiment on water levels in test well 1. This water contained in the fill, only a part of the total experiment is discussed on page 4 7. The artificial can be readily recovered by wells. recharge experiments showed that the area is Meinzer (1923a, p. 10-11) reported the follow­ definitely one in which natural recharge occurs and ing determinations of the porosity of rock ma­ in which artificial recharge is possible. terials : the range in porosity of uniform sands

STORAGE was from 26 to 47 percent, the average being 35 In water-table aquifers, water fills the voids or percent; mixed sands ranged from 35 to 40 per­ spaces between the mineral grains that form the cent and averaged 38 percent; clay ranged from aquifers; in artesian aquifers, the water fills the 44 to 4 7 percent and averaged 45 percent. Field voids and also is under pressure, because it is con­ tests of porosity of glacial materials in Pomperaug fined by overlying and underlying beds that are Valley, Conn. (Meinzer, 1923a, p. 11), showed the less permeable than the aquifers. Because water following: Fine stream-deposited sand, 48 percent; is slightly compressible and because the materials various glacial-outwash sands, sand-gravel mix­ that make up artesian aquifers are slightly elastic, tures, and silt and clay, 18-37.6 percent; and lake­ the removal of water from an artesian aquifer deposited silt, 36 percent. results first in an overall pressure adjustment Available information on the porosity of uncon­ within the aquifer, rather than the actual dewater­ solidated materials and on the character of sedi­ ing of the aquifer. As more and more water is mentary materials underlying the Weber Delta removed from an artesian aquifer, parts of the district suggests that an estimate of 25 percent aquifer may be dewatered. When this happens, porosity for the entire body of sediment is reason­ the aquifer reverts to water-table conditions and able and conservative. In the discussion on sub­ continued declines of water level reflect the un­ surface geology (p. 30), it was estimated that the watering of the sediments, rather than the com­ prism of unconsolidated sediments underlying the pression of the aquifer. district (excepting the Kaysville-Farmington sub­ The principal aquifers in the Weber Delta dis­ district and the northwestern part of the Ogden­ trict are artesian, and calculations were made to Plain City subdistrict) has a volume of about 200 determine the total amount of water in storage in cubic miles. From this estimate, the following the aquifers and to determine how much they would calculation may be made: yield for different changes in head. The yields 200 cubic miles x 640 acres x 5,280 feet x 0.25 were calculated for changes in pressure before (porosity) = about 170,000,000 acre-feet. dewatering the artesian aquifers and also for The estimated volume of 170 million acre-feet of changes after dewatering began. The calculations water is contained in the sedimentary prism that were based on data obtained by measuring wells, constitutes about three-fourths of the Weber Delta by pumping tests, and by recharge experiments. district and has a thickness of about 6,000 feet of VOLUMES OF WATER IN THE GROUND-WATER RESERVOIR fill at the deepest point. Much of this water in The quantity of ground water in storage in the storage is unavailable or of poor quality. It is Weber Delta district could be determined if the desirable, therefore, to consider how much of this volume and porosity of sedimentary materials were water is available for use by determining the known. Available data, however, permit only effects of changes in storage on the piezometric approximate calculations, and these calculations surface. must be considered from several points of view. Data from the Bureau of Reclamation test well CHANGES IN STORAGE IN THE WEBER DELTA SUBDISTRICT 5B, (B-5-2) 16dcd-2 (pl. 4), indicate that at depths Changes in artesian pressure are the results of between about 1,300 and 3,007 feet (maximum elastic adjustment of the aquifer materials and 46 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT the materials making up the confining layers of fers. This water would be obtained by lowering the system. The amount of water actually taken water levels in the artesian aquifers and in the into or released from an artesian aquifer, when recharge area, where ground water is under water­ pressure is increased or decreased, is very small, table conditions, by an assumed maximum of 150 because the volume change results from very slight feet. In the following discussion, the number and contraction or expansion of the water and by slight distribution of the wells that would be involved has structural adjustments among the mineral grains not been considered. composing the aquifer. Pressure changes caused Estimates of active storage have been calculated by adding water to, or withdrawing water from, for the artesian aquifers in the Weber Delta sub­ the artesian system appear to be out of proportion district by two methods : ( 1) using the artesian to the volume of water added or withdrawn. coefficient of storage of 8 x 10-4, or a calculated The extent to which small changes in amounts change in storage of about 300 acre-feet for a of water in the system can cause relatively large change in pressure of 5 feet, and (2) using data changes in pressures in wells is illustrated by the obtained from the recharge experiments. The two following calculations for an area corresponding calculations give reasonably comparable results. approximately to the Weber Delta subdistrict, ex­ The first method indicates that about 100,000 acre­ cluding 10 square miles of the subdistrict in which feet in excess of annual recharge might be removed ground water is unconfined (p. 47). The area in­ from storage in the artesian and nonartesian aqui­ cludes about 130 square miles which is largely fers of the Weber Delta subdistrict before dewater­ underlain by the Delta aquifer (pl. 5). The re­ ing of the artesian aquifers began ; the second sults of three aquifer tests at wells penetrating the method indicates that about 80,000 acre-feet might Delta aquifer (table 8) indicate an average co­ be withdrawn from the same area without dewater­ efficient of storage (see definition, p. 52) of ing the artesian aquifers. 4 8 x 10- • This average figure is within the range METHOD 1 cited by Brown (1953, p. 849) as being character­ Three factors must be considered in estimating istic of storage coefficients in artesian systems, active storage in the artesian aquifers of the and it is considered reasonable to use in calcula­ Weber Delta subdistrict. First is the lowering of tions. During the period December 1954 to De­ artesian pressure. As has already been shown, cember 1955, the average decrease in artesian even small changes in amounts of water in pressures in the Weber Delta subdistrict was 5 feet, storage in artesian systems may result in relatively and the decrease in storage that caused that water­ large changes in pressure head. Water levels level decline is calculated to be as follows: 4 range from 20 feet above to more than 150 feet (8 x 10- ) x 130 square miles x 640 acres below the land surface in the subdistrict, but for x 5 feet head differential = 333 acre-feet. convenience in calculation it is assumed that the Thus, a change in a storage in the artesian average water level is 50 feet below the land aquifers of about 300 acre-feet may lower the surface. piezometric surface about 5 feet. The many un­ Second, it is assumed that water levels will certainties involved in the data-the small number decline an average of 150 feet. Thus, no actual de­ of aquifer tests, the large area, the partial separa­ watering of artesian aquifers will take place be­ tion of the artesian system into semiindependent cause water levels will be at or above the top of aquifers, and the use of wells of many differing the Sunset aquifer which is at an average depth of depths to obtain an average value of 5 feet of 200 feet below the land surface. change in the piezometric surface-suggest that Third, it is assumed that the water table will the value obtained by calculation is not strictly decline at about the same rate as do artesian pres­ accurate. The 5-foot average decline in head ob­ sures. For this assumption to be valid, it would served between 1954 and 1955 in aquifers underly­ be necessary to have wells drawing from the ing an area of 130 square miles probably reflected water-table aquifer as well as from the artesian a decrease of water in storage of less than 1,000 aquifers. acre-feet. Using the above assumptions, the following cal­ ACTIVE STORAGE IN THE WEBER DELTA SUBDISTRICT culations can be made: The term "active storage" may be used to de­ Water released by lowering the artesian pressure 150ft Acre- feet scribe the water that can be readily developed and in the artesian aquifers in the Weber Delta sub- manipulated without dewatering the artesian aqui- district (60 acre-feet per foot of pressure decline) ____ 9,000 GROUND WATER 47

Water released by lowering the water table 150 ft in Acre- dip of the principal recharge area (see p. 38)-a rna t ena· 1 w1t· h an average spec1'fi c y1e· ld o f 10 percent feet zone about half a mile wide extending 5 miles (assumed) in an area of 10 square miles south and 4 miles north of the fan, with a total 150 X 10 X 640 X 0 .10 = ______96,000 area of about 5 square miles. Thus, the total area Thus, about 100,000 acre-feet of water in excess of the unconfined aquifer in the Weber Delta sub­ of annual recharge might be removed from storage district is on the order of 10 square miles. An in artesian and nonartesian aquifers in the Weber area of 130 square miles, mostly in the Weber Delta Delta subdistrict before dewatering of the arte­ subdistrict, is underlain by artesian aquifers (p. sian aquifers began. This may be a conservative 36). figure because as artesian pressures decline, the Using an average storage coefficient of 8 x 10-4 hydraulic gradient through the confining beds (from p. 46), and an average head increase of 3.5 between the artesian aquifers and the overlying feet, the increase in storage in the confined zone unconfined aquifers in places may be reversed. resulting from the test is computed to be about Thus, the artesian aquifers may receive additional 200 acre-feet, as follows: recharge from the beds directly above. (8 x 10-4 ) x 130 square miles x 640 acres x 3.5 feet= 230 acre-feet. METHOD 2 The amount of water taken into storage in the un­ Estimates of active storage also can be made by confined aquifers near the mouth of the canyon is using data from artificial recharge experiment 4 then conducted by the Bureau of Reclamation. 1,500 (the total amount infiltrated) - 230 From November 11, 1957, to February 11, 1958, = 1,300 acre-feet (rounded). about 1,500 acre-feet of water from the Weber Using the above figures and assuming that the River was put into a recharge pit at the mouth of coefficients of storage and the areal extent of both Weber Canyon, and the effects on water levels or the confined and unconfined aquifers would remain artesian heads were measured in nearby wells. about the same for an assumed maximum water­ The increases in head, as shown in the following level decline of 150 feet, the change in storage tabulation, were the changes measured in the vari­ (6.) in the fan-shaped part of the unconfined zone ous wells after the initial ground-water mound in is computed as follows: the recharge area had dissipated. 5.5 feet 1,300 acre feet

-~------c------150 feet D. or ~ = 35,000 acre feet. Distance from I . Head increase recharge pit Type of aqmfer Well and location 1 (feet) (miles) well penetrates As the area of the fan-shaped part of the uncon­ ------1------1 Bureau of Reclamation: fined zone constitutes about half of total unconfined Test well 1, (B-5-1) 36bbb-L ______6.0 0.3 Water table. area, the total change in storage in the unconfined Test well 3A, (B-5-1) 27dcc-1. ______, 1.8 Do. zone would be 70,000 acre-feet. The change in 5.o I'

Hm Field 4, cB-5-1) 33cda ___ 5.0 I 3.4 Artesian. Layton a, (B-4-1) 8add ______4.6 Do. storage in the confined zone has been calculated in

Sunset, (B-5-2)25bcd-2 ______1 6. 7 Do. 1 U.S. Bureau of Reclamation: I tg II method 1 as 9,000 acre-feet (p. 46); thus, the total test well 5A, (B-5-2) 16dcd-1. ______4.0 9.3 Do. change in storage for a water-level decline of 150 1 P~evedale, (B-6-2)33ddc _____ 3.0 I 10.5 Do. Bmgham, (B-5-2)31cbc ______2. 5 I 10.5 Do. feet would be about 80,000 acre-feet. Arave, (B-5-2)18cba ______11.9 Do. 1 2.5 WATER RECOVERABLE BY PARTIAL DEWATERING OF THE ARTESIAN AQUIFERS

These data show that the average rise measured WEBER DELTA SUBDISTRICT was 5.5 feet in the unconfined (water-table) zone and 3.5 feet in the confined (artesian) zones. Estimates of the amount of water recoverable by If the unconfined zone affected during the re­ partial dewatering of the artesian aquifers in the charge experiment extends outward from the Weber Delta subdistrict have been made (1) by mouth of Weber Canyon for a distance of at least applying arbitrary figures for specific yield to the 2 miles, as data from Bureau of Reclamation test sediments below 200 feet and (2) by re-estimating well 3A indicate, and if the zone has the rough the amount of water recoverable based on a specific shape of a 140° segment of a circle with a 2-mile yield calculated from the recharge experiments. For both estimates it was assumed that the maxi­ radius, then the area of the zone is ~~g X 7r X (2 mum depth from which usable water may be re­ miles) 2 or about 5 square miles. In addition to covered economically is 1,300 feet below the land this area, the aquifers in the Weber Delta sub­ surface. The first method indicates that if the district contain unconfined water in and just down- upper 50 feet of the artesian aquifer were de- 48 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT watered, the volume of water recoverable would be The calculations show that about 13 million acre­ about 600,000 acre-feet; the second method indi­ feet of water theoretically is available for with­ cates that 300,000 acre-feet of water would be re­ drawal from the 1,100-foot prism of sediments in coverable if the upper 50 feet of the artesian the 130 square miles underlain by the artesian aquifer were dewatered. Despite the wide range, aquifers in the Weber Delta subdistrict. Of course, the estimates of the amount of water available by only part of this amount can be manipulated dur­ partial dewatering of the artesian aquifers in the ing the operation of the subsurface reservoir. Weber Delta subdistrict seem reasonable for use Complete dewatering of the 1,100 foot thickness as minimum and maximum values. would be required to obtain the 13 million acre­

Method 1 feet in storage-and such dewatering is neither desirable nor possible. It is feasible, however, to Calculations of the amount of water in storage consider dewatering a few tens of feet of the in the 1,100-foot thick prism from 200-1,300 feet artesian aquifer. Thus, if we assume that a thick­ in the 130 square miles underlain by the Delta and ness of 50 feet of aquifer might be dewatered dur­ Sunset and deeper artesian aquifers in the Weber ing a period of crisis, such as a long drought, the Delta subdistrict are based on interpretation of amount of water recoverable would be about 600,- plate 3 by applying arbitrary specific yields of 000 acre-feet. 25 percent for the coarser materials and 5 percent The calculations of yield by method 1 are based for the finer materials. These values are general­ on the assumption that the sediments will actually ized from estimates of specific yield by Thomas­ give up a percentage of water equal to the esti­ son, Olmsted, and LeRoux ( 1960, p. 283-287). It mated specific yield-5 percent for fine-grained is assumed further that the clay-silt percentage material and 25 percent for coarse-grained ma­ shown on plate 3 represents the distribution of fine terial. The calculation of specific yield by method materials throughout the interval from 200-1,300 2 which follows, however, indicates that the coarse­ feet below the land surface and that the sediments grained materials will not accept, and hence prob­ are saturated throughout that depth. ably not yield, water at the rate calculated by The following areas were obtained from plate 3: method 1. Therefore, the estimate of 25 percent Percent of underlying Area materials that is for coarse-grained materials as used in method 1 (square miles) fine grained 2 ______~-20 may be too high. 17 ______20-40 Method 2 45 ______40-60 64 ______60-80 As previously estimated on page 47, the quantity 2______80 of water taken into storage in the nonartesian aqui­ fers during the recharge experiment was about For those areas having a range of fine-grained 1,300 acre-feet, and this resulted in a rise in head material, the median value was used in the follow­ of 5.5 feet. Over an area of 5 square miles, or ing calculations: 3,200 acres, this 1,300 acre-feet is equivalent to an Area Fine-grained materials Coarse-grained materials average depth of 0.4 foot of water. Therefore, the Area-grain Area-grain coefficient of storage or specific yield of these Square miles Percent size factor Percent size factor (sq mil (sq mil materials is g:~ = 0.073 or 7.3 percent. This is 2 20 0.4 80 I 1.6 17 30 5.1 70 11.9 slightly less than the specific yield of 10 percent 45 50 22.5 50 22.5 that was assumed when estimating the yield of 64 70 44.8 30 19.2 1.6 20 .4 the unconfined aquifers (p. 47) and appreciably ------smaller than the specific yield of 25 percent that TotaL ___ l3: 74 ------56 ~-----~~- was used to calculate the water to be obtained by The amounts of recoverable water in storage were dewatering the coarse-grained materials of the calculated as follows : artesian aquifers (see Method 1). 74 x 640 acres x 1,100 feet x 0.05 specific yield By using a specific yield of 7.3 percent, the water = 2,600,000 acre-feet, or about 3,000,000 acre-feet recoverable by dewatering the coarse-grained ma­ recoverable from fine-grained material. terial in the artesian aquifers is shown in the fol­ 56 x 640 acres x 1,100 feet x 0.25 specific yield lowing calculation: = 9,900,000 acre-feet or about 10,000,000 acre-feet 56 x 640 acres x 1,100 feet x 0.073 specific yield recoverable from coarse-grained material. = 3,000,000 acre-feet. GROUND WATER 49 If an additional 3 million acre-feet of water is re­ Hill Air Force Base, an area of heavy pumping coverable from fine-grained material (p. 48), the (Smith and Gates, 1963, pl. 2). Elsewhere in the total recoverable from both fine- and coarse-grained district, although there is general decline in arte­ material would be about 6 million acre-feet. Thus, sian pressures, flowing wells continue to flow. if the upper 50 feet of aquifer were dewatered, the Considering the relatively large change in pressure volume of water recoverable would be about 300,- head that results from a small change in the volume 000 acre-feet. of water in storage, as calculated in this report OTHER AREAS (p. 46), it appears that the amount in storage in Calculations were made to determine the maxi­ the district has changed little in the period 1936-61. mum amount of water recoverable from other areas The production of additional water from the aqui­ in the Weber Delta district. The calculations were fers is possible, although if a large volume of water made before the Weber Delta district was divided is produced, a significant lowering of pressure head into subdistricts; therefore, some of these areas do will result. The rate of decline of pressure in re­ not correspond exactly with subdistricts. However, sponse to increasing draft upon the aquifers can­ the Kaysville-Farmington area is equivalent to the not, at this stage of knowledge, be predicted; but Kaysville-Farmington subdistrict; the Ogden-West estimates of the amount of water that might be Ogden area includes all the Ogden-Plain City sub­ withdrawn by lowering the pressure a specific tHstrict, except its northwestern part; the North amount were given in the discussion on storage. It Ogden area is about the same as the North Ogden is certain, however, that effective development of an subdistrict; and the western and northwestern areas artesian basin requires that the pressure be lowered include the Little Mountain subdistrict, most of the so that recharge to the system may be increased w·est Warren subdistrict, and the northwestern and so that wastage may be reduced. Smaller arte­ part of the Ogden-Plain City subdistrict, excluding sian flows-or a change from flowing wells to the salt flats bounding this area on the west and pumped wells-is the price that must be paid for northwest. the full development of an artesian system.

The calculations that follow were made using 25 DISCHARGE percent as the specific yield of coarse-grained ma­ Ground-water is discharged in the Weber Delta terials; hence, they should be considered as maxi­ district from both flowing and pumped wells, as mum values. well as by natural means, such as springs, seep­

Water obtainable age into drains and sloughs, and by evaporation Water stored by dewatering Area in zone topmost 50 ft of and evapotranspiration from croplands, open-water Area (sq mi) 1,100 ft thick aquifer 1 (acre-feet) (acre-feet) surfaces, saltgrass pastures, cattail swamps, and Kaysville-Farmington_!--~~ 3,000,000 90,000 mud surfaces. Detailed studies of evaporation and Ogden-West Ogden ___ . 55 5, 000,000 200,000 transpiration were made to determine the total North Ogden______11 I 800 , 000 40 , 000 Western and amount of water that is discharged from the dis­ 1 ~n_o_rt_h_w_e_st_er_n_a_r_e_as_2---'l~~-89__c__8~,o_o_o___c._oo_o__._~-~-4_00. 000 trict, and these studies are discussed in the section 1 In addition to amount obtainable by lowering the artesian pressure to the top of the artesian aquifer. In the Weber Delta subdistrict this amounts to 80,000- on evaporation and evapotranspiration. 100,000 acre-feet. Comparable amounts presumably could be obtained from other areas. DISCHARGE FROM WELLS 2 The preponderance of fine-grained materials in this area would materiallY restrict development of water in storage. · Discharge from wells is only a small part of the total discharge of ground water in the Weber Delta LONG-TERM FLUCTUATIONS IN ARTESIAN PRESSURE district. It is, however, that part of the total dis­ Water levels in many observation wells in Utah charge which is under man's control and which is have been measured periodically by the U.S. Geo­ best known. The district contains many pumped logical Survey since 1935. Hydrographs of selected wells of large yield and thousands of flowing wells wells in the Weber Delta district are presented on -characteristically those used by individuals for plate 8 to show long-term fluctuations, which are domestic or stock supply. In 1954, discharge from related to changes in volumes of water in storage wells of both categories was determined to be about in the aquifers. 25,000 acre-feet (table 7). A general decline was recorded in many wells Most of the pumped wells of large yield are east during the period 1953-61, although some wells do of the 4,300-foot topographic contour, in areas not show the decline in pressure head (Smith and where wells do not flow. All wells in the area that Gates, 1963, p. 25). The maximum declines in the have large yields tap the Delta aquifer. These Weber Delta district are in the general vicinity of wells range in diameter from 8 to 20 inches and dis- 50 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

TABLE 7 .-Discharge from zoells in the lVeber Delta district in 1954 same township furnishes part of the water supply Flowing wells for the town of South Weber. ------Township Acre-feet i 1· Township I Acre-fe~.t Warm springs, which discharge water that con­

T. 3 N., R. 1 E ____ _ 250. T.6N.,R.2W _____ I 2,700 tains a relatively high content of dissolved minerals, T. 3 N., R. 1 W ___ _ 2,000 T.6N.,R.3W_____ 750 are principally in three locations in the district T. 4 N., R. 2 W ___ _ 3,700 f T. 7 N., R. 1 W _____ 3,000 T. 5 N., R. 2 W ___ _ 2,200 T. 7 N., R. 2 W_____ 500 (fig. 12). Utah Hot Springs, which discharge T. 5 N., R. 3 W_ _ _ 1,600 T.7N.,R.3W _____ 1 220 about 2 cfs, emerge from Cambrian quartzite

T.6N.,R.1W ___ _ 800 1 --- Subtotal ______; 17,720 approximately on the Weber County-Box Elder ------Pumped wells of large yield County line in sec. 14, T. 7 N., R. 2 W. The tem­ perature of water from these springs is 134°F, Owner Coordinate Acre-feet and the water has been used in the past for public Kaysville ______(B-4-1) 130 Kaysville Canning Co ______(B-4-1) 140 baths. The spring area is marked by extensive Layton ______(B-4-1) 150 iron-stained deposits, and the saline water (table Woods Cross Canning Co ______(B-4-2) 140 Smith Canning Co ______(B-4-2) 120 10) contaminates ditch water for miles distant West Point______(B-5-2) 40 from the source. The water also has a high natural Syracuse ______(B-4-2) 120 Clearfield ______(B-4-2) 1,090 radioactivity (table 10).

Naval Supply Depot Clearfield ______(B-4-2) i 730 El Monte Spring, near the mouth of Ogden Washington Terrace ______(B-5-1) ! 440 South Ogden ______(B-5-1) 200 Canyon in sec. 23, T. 6 N., R. 1 W., supplies heat Hill Air Force Base ______(B-5-1) 1,630 for a public swimming pool. The discharge was Ogden ______(B-5-2) 1,320 Riverdale ______(B-5-1) 120 not measured during the investigation, but it is (B-5-2) 320 some tens of gallons per minute, at 135°F. The (B-5-2) 550 Other~~~~~t~~======i ______430 water is less saline (table 9) than that of Utah Hot Springs (table 10) and discharges into the Subtotal ______7,670 Ogden River. The spring emerges from rock of Total (rounded) ______25,000 the Wasatch Range at an altitude of about 4,520 feet above sea level-far above the general level of charge from 200 to 1,800 gpm. Pumping lifts range artesian flow in the district-whereas Utah Hot from 100 to 400 feet, depending on location, and the Springs emerge at 4,300 feet, an altitude that gen­ depth of the wells ranges from 300 to 1,000 feet. erally is the upper limit of artesian flow in the Most flowing wells are below (west of) the 4,300- district. foot topographic contour, except in the North Og­ Hooper Hot Springs, in sec. 27, T. 5 N., R. 3 W., den subdistrict. The flowing wells are of small form a mound about one-eighth of a mile in diam­ diameter, commonly 2 inches, range in depth from eter on the flatlands near the shore of Great Salt 100 to 800 feet, and discharge from less than 1 to Lake. A series of orifices discharges a total of 80 gpm. about 15 gpm of saline water (table 10), which is DISCHARGE BY SPRINGS dissipated by evapotranspiration in saltgrass mead­ Discharge by springs, which is on the order of a ows. The highest water temperature measured few thousand acre-feet per year, constitutes a very was 140°F. A few small satellite warm springs small part of the total discharge of ground water are nearby. in the Weber Delta district. Several springs dis­ A line of low spring mounds extends northwest­ charge water ranging in temperature from 50° to ward from Hooper Hot Springs toward the south­ 60°F along the mountain front, and local recharge ern tip of Little Mountain (fig. 12). Most of them supplies water for a few seeps and small springs discharge small volumes of moderately mineralized along the edge of the delta deposits, especially in warm water to the mudflats of Great Salt Lake. the valley cut by the Weber River. Most of the The mineral content of the water apparently dif­ springs in the district are of small yield, typically fers, as some of the mounds support growths of only a few gallons per minute. sunflowers and other plants that are thought to A group of springs of large yield, however, is in require water of low mineralization, whereas other sec. 36, T. 5 N., R. 1 W. The total discharge of mounds are not vegetated or bear only salt-tolerant these springs is on the order of hundreds of gallons plants, such as pickleweed and saltgrass. per minute, and they were used as a source of sup­ Warm saline water rises along the Warm ply for many years by military installations on the Springs fault in the Bountiful district (Thomas Weber Delta. Another spring in sec. 25 of the and Nelson, 1948, p. 115-118) and probably rises GROUND WATER 51

R. 3 W. R. 2 W. R.l W. R.l E. [~]\ / __ _) z oz<( ) BOX ELDER CO I /----wEBER co__ _ ------~/ 5 )7 T. 7 N. Utah Hot Springs ~ (j) I / 17 11 I II o• (8-7-1) 33 baa-5 -A 0 f/ Plain City J_----_f North Ogden () ------+--..::o~--~(B::._-_:_7_-1) 32 ada-4 1 o "!. I o--+------0~------+---~------~ Little c;--,~ (B-6 - 2 ) 1 baa-3 (B-6-1) 4 ada-1

Mountain t; JJ ..______0 (B-6-3) 15 dad-1 ~ \ o \ TW4A• ) (8-6-2) 11 dad-1 , ~ 0 ~ <( T. 6 N. c\\ ...J West Warren (B-6-2) 26 -1 \ 3 fir 0 ~ a a • ElM 's · \ o '>I 1W2 IOgden ~ ___-onte pnng I 4 (B~ 26~'bbb-1 : c\' ~ ~ ~ -~~~~1\29 abb-1 \.(l 0 ° ~ OGDEN I (8-5-2) 6 bdd-t ~-+--\H-----l------1----+------l 1 ...;., \ / J r5l cJ21 ~ ?J \ \, / (8-5-2) 16 dcd-1, 2 :) (f) 2o ~ / Hooper TW5A and 58 ( • (B-S- ) dcc- , (;) ~ 1 27 1 2 T. 5 N. EXPLANATI0~~ ... 5-3L13 dd~--+---WEBE; co _ __3t£,v \ TW3A and 38 I rn \ I 1 DAVIS CO 17 -~ j~ (8-6-3) 26 bbb-1 ~Hooper Hot Spn:ngs ~. 16 ....._ vB-5-1) 36 bbb-1 o '\i I Sunset'-- 12'~Qd ~3--.. _____ 6 WebeTJW1 River

Well having long-term hydrograph ~'----. d(B-5-3) 36 ada-1 GATEWAY TUNNEL shown on plate 8 ; for explanation . of numbering system see text \-~-----<(}-----~C~le~a~r~f~te:_:ld+-----~.,.._...:::o~(~B~-::..:5~-=-=.1 )!....::!.3~3~c~d~a~-:.=1'------i HILL AIR FORCE BASE • TW3A 1~ 12 bbb-1 a 1 Bureau of Reclamation test well 0 Syracuse Well pumped for aquifer test; 9 T. 4 N. number refers to table 8 (8-4-1) 19 cdl ~'-t:f"' Jr- 1tl Layton 0 0

0 Well pumped for aquifer test and Kaysville having long-term hydrograph ~ (8-4-1) 34 cbc-3 (Qt • shown on plate 8 ; number refers 1 8 to table \ ~..... 1a--.---~------l

0 ------~'--'"'/\ Observation well used during an Approximate line of warm springs aquifer test between Hooper Hot Springs and \ Little Mountain T. 3 N. @ (8-6-1) 29 abb-1 Farmington 0 0 bserv a tion well used during an Maximum distance over which ef­ aquifer test and having long-term fects of pumping were observed hydrograph on plate 8 during aquifer tests ~\~

Oil test Gaging Station >---- 0 3 4 5 MILES Spring Tunnel entrance

FIGURE 12.--Map of the Weber Delta district, Utah, showing selected hydrologic data. 52 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT along faults at several places in the Weber Delta normal to that surface. This coefficient is a dimen­ district. The linear arrangement of the mounds on sionless number. The coefficient of storage of a the salt barrens implies that they mark the trace nonartesian aquifer is nearly identical with the of a fault. Evidence of faulting is conspicuous at specific yield of the aquifer. Specific yield is Utah !f·ot Springs and is probably present at El defined (Meinzer, 1923b, p. 28) as the ratio of the Monte Spring. Wells near the thermal springs volume of water which, after being saturated, a yield saline ground water, thus suggesting that rock or soil will yield by gravity to its own volume. there is some discli'arge of salty ground water In an ideal aquifer test, there should be a through fault zones into the aquifers. pumped or flowing well and one or more observation wells, all fully penetrating the same homogeneous AQUIFER TESTS HYDRAULIC CHARACTERISTICS extensive aquifer. No other wells should be dis­ Twenty aquifer tests were made to determine hy­ charging from the aquifer. The depths of the zones draulic characteristics of the aquifers in the Weber of perforation of the wells should be known. The Delta district. The wells used in making these coefficients of transmissibility and storage are tests are shown in figure 12. The results of the assumed to be constant at all times and in all parts tests are given in table 8. The Bureau of Recla­ of the aquifer. mation made 15 of the tests between December 1952 Unfortunately, not all the above conditions could and February 1956. The other five were made by be met in the Weber Delta district. The district the Geological Survey between October 1944 and contains numerous interconnected aquifers and in June 1946. Data from all tests were analysed using many places the degree of penetration of a par­ procedures described by Theis (1935) or by Jacob ticular aquifer by a well could not be determined. and Lohman (1952). Observation wells were not available in some of the The ability of an aquifer to transmit water is test areas, and in some areas the flow from wells expressed by its coefficient of transmissibility, not being used in the test could not be controlled. which is expressed as the rate of flow of water, at Of the 15 tests by the Bureau of Reclamation 12 the prevailing water temperature, in gallons per were made on pumped wells, keeping the discharge day, through a vertical strip of the aquifer 1 foot constant and allowing the drawdown to vary. The wide extending the full saturated height of the data obtained were analysed by means of a formula aquifer under a hydraulic gradient of 100 percent. derived by Theis (Brown, 1953, p. 852). Of the The coefficient of storage of an aquifer is de­ 12 tests, 9 were of artesian aquifers and 3 of water­ fined as the volume of water it releases from or table aquifers. The other 3 tests were made on takes into storage per unit surface area of the flowing wells, keeping the drawdown constant and aquifer per unit change in the component of head allowing the discharge to vary with time (Jacob

TABLE 8.-ResuUs of aquifer tests in the Weber Delta district i Coeffi- Pumped Type cient of Coefficient Test 1 Date Subdis- Well Well or of Aquifer transmis- of I Tested of test trict 2 depth flowing aquifer sibility storage by well (gpd/ft)

1 10-31-44 OP (B-6-1)28dab 600 Pumped Artesian ------300,000 ------U.S. Geol. Survey. 2 1-17-45 WD (B-5-2 )1 ddd-1 527 ___ do ______do ______Delta 36,000 ------Do. 3 4-13-45 OP (B-6-1)21add-1 210 ___ do ______do ______------130,000 Do. I ------4 6-28-45 WD (B-5-2)1ddd 472 ___ do ______do ______Delta 64,000 ------Do. 5 6-19-46 WD (B-5-2)12aab 507 ___ do ____ , _____ do ______do __ 84,000 ------Do. 6 12-18-52 WD (B-5-1)36bbb-1 3 217 ___ do ____ I Water table ------30,000 ------U.S. Bur. Reclamation. 7 4-27-53 WD (B-4-2)12bbb-1 774 ___ do ____ Artesian Delta 190,000 7.9X10-4 Do. 8 8- 7-53 KF (B-3-1)1bbc-1 300 ___ do ____ Water table 40,000 ------Do. 9 10-14-53 WD (B-4-1)19daa-1 616 ___ do ____ Artesian Delta 110,000 1.5X10-3 Do. 10 10-22-53 NO (B-7-1 )33bac-5 252 Flowing _____ do ______------4,000 2. 5 X10-4 Do. ___ do ______do ______11 11- 4-53 NO (B-7-1)29cdb-2 165 ------5,000 ------Do. 4 _____ do ______12 11-30-53 WD (B-5-1)27dcc-1 350 Pumped ------110,000 ------Do. 5 ___ do ____ 13 12-29-53 WD (B-5-1)27dcc-2 115 Water table ------40,000 ------Do. 6 4 14 4- 6-54 OP (B-6-2)26ada-1 600 Flowing Artesian ------15,000 3.9X10- Do. 15 12- 8-55 WD (B-5-2)13dad 514 Pumped _____ do ______Delta 95,000 Do. _____ do ______------16 12-12-55 WD (B-5-2 )25bcb-2 704 ___ do ______do __ 25,000 ------Do. 17 12-13-55 WD (B-5-2)25bbc 505 ___ do ______do ______do __ 70,000 Do. ___ do ____ ------18 12-15-55 KF (B-4-1 )35cdb-1 260 _____ do ______------2,000 ------Do. 19 1- 9-56 WD (B-4-2 )2dad 675 ___ do ______do ______Delta 110,000 6.6X10-5 Do. I ___ do ______do ______do __ 20 2- 8-56 I WD I (B-5-1 )17 cbd-1 550 120,000 ------Do. 1 Locations of test wells are shown in figure 12. 4 U.S. Bur. of Reclamation test well 3A. 2 KF, Kaysville-Farmington subdistrict; NO, North Ogden subdistrict; OP, 5 U.S. Bur. of Reclamation test well 3B. Ogden-Plain City subdistrict; WD, Weber Delta subdistrict. 6 U.S. Bur. of Reclamation test well 2. a U.S. Bur. of Reclamation test welll. GROUND WATER 53 and Lohman, 1952). The 5 tests by the Geological The rates at which the cones develop and spread Survey were made on artesian aquifers using are related to the fundamental difference between pumped wells. water-table and artesian conditions. Under water­ The tests in the Weber Delta subdistrict (table table conditions, the cone develops slowly because 8) indicate that aquifers to depths of about 700 feet considerable water must drain by gravity from have fairly large coefficients of transmissibility. the pore spaces in the aquifer in order that a cone Therefore, it is likely that the amount of recharge, of depression may form. Under artesian condi­ rather than the coefficient of transmissibility, will tions, the cone of pressure relief spreads much more be the limiting factor in ground-water development rapidly and over a greater area than does the of the subdistrict. water-table cone. Outside the Weber Delta subdistrict, it was dif­ The reason for the widespread and rapid effect ficult to find both a suitable discharging well and of pressure relief in an artesian aquifer is found suitable observation wells at a given location. A in one of the fundamental principles of the be­ few tests made, however, indicate that aquifers in havior of a hydrostatic system. In an ideal case, the North Ogden subdistrict have a much lower where pressure is applied to-or removed from­ coefficient of transmissibility than does the Delta any point in a confined body of fluid, the pressure, aquifer; the aquifers in the Ogden-Plain City sub­ or release of pressure, becomes immediately effec­ district have a relatively large average coefficient tive at all other points in the fluid body. The of transmissibility; and the aquifers in the Kays­ artesian aquifer constitutes such a confined body ville-Farmington subdistrict have considerable in that the water is the fluid, and semipermeable range in transmissibility. layers above and below the aquifer confine the All 20 aquifer tests were made in the eastern water. The artesian aquifer differs from the ideal part of the Weber Delta district, where conditions case, however, in two important respects. The for testing were most favorable. A definite need gravel and sand composing the aquifer offer fric­ exists for aquifer tests in the western part of the tional resistance throughout the system, and the district, but this area contains few wells suitable system is not completely confined because the layers for testing. The wells in the western part of the of silt and clay that lie above and below the aquifer district are almost all of small diameter; they are are not entirely impermeable. Furthermore, the used mainly for domestic purposes at individual system must be effectively open at the upper end, homes; and they were all flowing during the period else recharge could not occur. 1953-56. Many well owners refused to permit their The "open-end" system is comparable to a city wells to be closed, because they cannot be without water-supply system where the reservoir-or mu­ water for extended periods of time and because nicipal standpipe-provides a body of water that sand enters the wells when flow is restricted. both supplies the system and, being elevated, causes pressure to form in the distribution pipelines. In WELL INTERFERENCE the Weber Delta district artesian system, the water Well interference is determined by the extent of in the recharge areas (the "reservoir" of the anal­ the cone of depression around a discharging well. ogy) near the mountains is at higher elevation than In a nonartesian aquifer, a local cone of depression the water in the aquifer (the "pipeline"), as the develops in the water table as the aquifer becomes aquifers dip deeper below the land surface pro­ dewatered in the immediate vicinity of a discharg­ gressively from the mountains toward the lake. ing well. The point of greatest depression is at the An artesian system rapidly (in theory instan­ well, which is the axis of an inverted cone, and the taneously) shows the effect of changing pressure. base of the cone is the surface of the water table. Although the effect is widespread, it decreases Under artesian conditions, the cone of pressure sharply with distance from the discharging well relief that develops around a pumping or flowing and, therefore, cannot be observed throughout a well differs from the cone of depression of the un­ large artesian aquifer. Nevertheless, the release of confined aquifer in that the artesian aquifer is not pressure that occurs when any well is allowed to actually being dewatered. The cone of pressure flow affects every part of the artesian aquifer, relief is imaginary, but it is similar in shape to the even though the effect at some distance is too slight cone of depression. That is, the pressure reduction to be measured. is greatest at the well, becoming less with increas­ During 9 of the 20 aquifer tests made in the ing distance from the well. Weber Delta district, measurable effects were ob- 54 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT served in observation wells. The maximum dis­ 4,300 feet, whereas elsewhere in the Weber Delta tance over which effects were observed was 3.2 district, the 4,300-foot topographic contour marks miles (fig. 12). Of course, if the tests had been the approximate upper limit of flowing wells. This longer or the rate of pumping greater, the area suggests that the North Ogden subdistrict may be affected probably would have been larger. During hydraulically separated from adjacent areas on the four tests, water levels in the observation wells west and southwest, by extensive clay deposits. were not affected, perhaps because the discharging In the eastern part of the Ogden-Plain City sub­ wells were not pumped long enough, or because district, opposite the mouth of Ogden Canyon, the discharging wells and the observation wells contours showing the piezometric surface in the were in different aquifers. No observation wells shallower aquifers bend toward the mountain (pl. were available during 7 of the 20 tests. 9). This suggests that the Ogden River supplies MOVEMENT little recharge to the ground-water aquifers. This DIRECTION suggestion is substantiated by the subsurface litho­ Ground water in the aquifers of the Weber Delta facies map (pl. 2) which shows that in the zone district moves down gradient in response to the extending from the surface to 200 feet the material influence of gravity. The direction of movement, near the mouth of Ogden Canyon is mostly fine in general, is westward, from recharge areas near grained and by seepage measurements in the Ogden the Wasatch Range toward Great Salt Lake. The River which show that, at periods of low flow, the pattern of movement is shown by the piezometric­ river does not lose much water to its channel (p. 41). surface map (pl. 9). This map was prepared on The map (pl. 9) includes contours on the the basis of water-level measurements from wells perched water table underlying the Weber River less than 400 feet deep and from wells from 400- flood plain in the eastern part of T. 5 N., R. 1 W. 700 feet deep. The pressures in the aquifers in the ( p. 41). These contours indicate that in this area district vary, usually increasing with depth; there­ the water table slopes generally eastward, opposite fore, plate 9, which was prepared by grouping wa­ to the westward gradient found in aquifers else­ ter levels from wells chosen on the basis of depth where in the Weber Delta district. VOLUME OF WATER MOVING THROUGH THE rather than aquifer, is greatly generalized and does WEBER DELTA SUBDISTRICT not portray conditions in any one aquifer. No Calculations based on permeability and hydraulic interpretations should be made that involve any gradient indicate that in the Weber Delta sub­ of the numerous small irregularities in the two district about 40,000 acre-feet of ground water piezometric surfaces as drawn, and calculations annually flows through the section between the sur­ made using the hydraulic gradients shown on the face and a depth of 1,300 feet. Some of this water map are at most approximate. is discharged by wells in the subdistrict, but Both the shallower and the deeper aquifers show probably about 20,.000 acre-feet continues westward generally similar configurations of the piezometric toward the lake. These calculations are based on surface, although the deeper aquifers provide a several assumptions, but the results seem to be of more varied pattern. The most significant feature the correct order of magnitude. Aquifer character­ of the map is the shape of the piezometric surface istics in other parts of the Weber Delta district are in the Weber Delta subdistrict. Here the contours too little known to permit a calculation of the bulge far westward and are widely spaced, indicat­ volume of water in motion. ing considerable recharge-much of it presumably The following method was used in calculating the from the Weber River-and suggesting that ma­ underflow. The permeabilities of various aquifers terials of the Delta and Sunset aquifers are highly in the area were calculated from the results of 13 permeable. aquifer tests (p. 52). The transmissibility deter­ Few wells are in the northern part of T. 7 N., mined from each test was assumed to be attribut­ and little is known about the movement of ground able to the total thickness of sand and gravel, as water in the area. The piezometric surface has a obtained from the driller's well log, between the steep gradient in the North Ogden subdistrict, in first clay layer above the perforated zone and the the southwest corner ofT. 7 N., R. 1 W. The steep­ first clay layer below the perforated zone. The ness may result from the slow movement of water transmissibility from each test was divided by this through the relatively impermeable clay that under­ total estimated effective thickness to get the per­ lies the subdistrict (pis. 2, 3). The subdistrict is meability. Then the permeabilities were plotted unique in that wells flow at altitudes greater than against the assumed grain size of the predominant GROUND WATER 55 330 I- ~ 1- 1- I=- 300 I L i- I- Estimated 1 '-- r- averagey VI 270 / '-- I - r- - r- - 0::: '-- I / v - :::> 240 0 - v - I ,..__ - - I - 0::: - - w 210 I 0.. I I - - - • I (/) Y' - w - - - - I 180 - I I u - v - z - Upp~v· •_,I - - limit - z - - 150 • I >-" - - t:: 1- ;·VLower - ....J 1- - 1- limit - ClJ 120 I • <( 1- v - w 1- - ~ 1- - 0::: 1- v - w 90 / I 'I 0.. 1- - 1- ~I - I- I - 1- - 60 / • .. / 1- / - 1- . - 1- - 1- ~ - ~,...- /: 30 / 1- v - 1- - I- ~ ~ - 1- ~ ---- - 0 ~ ----- 0.05 0.10 0.2 0.5 2 5 10 20 50 100 DIAMETER OF PARTICLE, IN MILLIMETERS

FIGURE 13.-Relation between permeability and assumed grain size.

material of the corresponding perforated zones of the well. A transmissibility was then deter­ (fig. 13), and a curve was drawn showing the esti­ mined for each class by multiplying the thickness mated average relationship between assumed grain of the class and the corresponding permeability size and permeability. The values shown below estimated above. The total transmissibility for the were then taken from the intersection of the esti­ full thickness of sand and gravel between the datum mated average curve and the median-size values of 4,300 feet and the bottom of the well was then for each grain-size class. The terms used by the determined by adding the calculated transmissibil­ drillers were assumed to be approximately equiva­ ities of the various classes of material. This value lent to the terms used in the U.S. Bureau of then was arbitrarily used to obtain the transmis­ Reclamation classification. sibility of the section between the bottom of the well and the altitude of 3,000 feet. The two values Estimated permeability Predominant material 1' Grain size 1 of transmissibility were added to produce a trans­ (from well logs) 1 Gal/ft 2/day In/hr ------1------missibility for the full 1,300-foot section. Projec­ Cobbles ______I 127 4,580 306 Coarse graveL ______-I 38.1 3,230 216 tion of the values of transmissibility from the GraveL ______1 19.1 2,420 162 tested wells to the entire thickness of 1,300 feet Fine graveL ______i 9.52 1,620 108 used in the calculation does involve a sweeping gen­ Coarse sand ______. 3 670 45 Medium sand ______1 .9 300 20 eralization. The records of a few deep test wells Sand (undifferentiated)_ i .6 209 14 Fine sand ______i .18 60 4 drilled by the Bureau of Reclamation and the 1 Median-size values for each grain-size class from classification of the U.S. Bur. results of seismic surveys, however, indicate that of Reclamation; assumed to be the median size for material described in well logs. similar alternating beds of coarse and fine ma­ The total thickness of each class of sand and terial persist to, and below, the altitude of 3,000 gravel was determined for each well from the log feet. This test drilling also indicated that condi- 56 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

tions may be favorable for future development of I Weighted-average I Calculated annual

year Month 1 gradient flow ground water to depths of 1,300 feet below the 1 J I (feet per mile) j __(a_c_re_-fe_e_t)_ land surface. 1961 /February___ ~ji. ~~:~~~ A line of reference was selected for the calcula­ 1960 · March _____ l ,600 June______3.22 39 00 tion of underflow through the Weber Delta sub­ September __ i 2. 01 34,7 district. This reference line was drawn through December_ _ 2 . 87 35,400 1954 March_____ 3.64 44,900 most of the wells used in the aquifer tests, hence June______2.87 '3345,480000 across the area where aquifer characteristics are September __ . 2.821' ' December __ . 2. 55 31,400 best known. The hydraulic gradient in the Delta I I aquifer was determined for segments of the refer­ Average______36,000 ence line using periodic water-level measurements wells upgradient from the line of reference, and made in 1960 and 1961 in wells tapping the Delta about 5,000 acre-feet is pumped in the vicinity of aquifer. The slopes of the water surfaces are gen­ erally similar in the Sunset and Delta aquifers, and the reference line. In addition, about 12,000 acre­ feet of water is discharged annually from flowing the configuration of the piezometric surface of each aquifer is also similar. Applying the hydraulic wells downgradient from the reference line. gradient, which was determined by using wells in The 3,000 acre-feet pumped east of the reference the Delta aquifer, to the entire section, including line was added to the 36,000 acre-feet of water mov­ ing past the line, to derive a total of about 39,000 the Sunset aquifer and zones below the Delta aquifer, probably does not introduce a serious error acre-feet that is calculated to move each year into the calculations. The line of reference and beneath the Weber Delta subdistrict. The 3,000 the gradient for March 1960, a typical hydraulic acre-feet withdrawn, however, does not reach the gradient in the Delta aquifer, are shown on plate line of reference along which the calculation was 10. The gradients for 1954 were estimated from made. the 1960-61 data. The gradients shown on the The total amount of water that moves westward piezometric surface maps (pl. 9) were not used in the Weber Delta subdistrict past the areas of because the 1960-61 data were more complete along withdrawal by wells and is discharged by upward the line of reference and because the data used to leakage and evapotranspiration and by seepage prepare plate 9 were not differentiated according into Great Salt Lake is about 19,000 acre-feet. to aquifers. This value was obtained by subtracting the total The volume of water moving under each segment withdrawal of 20,000 acre-feet from wells down­ of the line of reference on plate 10 was calculated gradient from the reference line from the ~ot~l of by using ( 1) the observed hydraulic gradient and 39,000 acre-feet moving through the subd1stnct. (2) the appropriate transmissibility calculated for The amount calculated to move through the sub­ the segment. The calculations were made using district, however, may be less than the actual the general equation: amount. Many of the wells measured to obtain the where hydraulic gradient are within the areas of inter­ Q =TIL ference of the pumped wells. Because most of Q = Volume of water in gallons per day. these pumped wells are on or upgradient from the T = Transmissibility in gallons per day per reference line, the hydraulic gradient between the foot. areas of influence of the pumped wells may actually I = Hydraulic gradient in feet per mile. be steeper than the gradient shown on plate 10 and, L = Length of the line segment in miles. therefore, the total discharge may be greater than The results of the calculations are summarized in 39 000 acre-feet. If the actual underflow is greater, the following table. In the summary, the amount th~n the actual discharge by evapotranspiration of underflow in gallons per day was converted to and seepage into the lake will be greater by the acre-feet per year, the total underflow past the line same amount. Perhaps 40,000 acre-feet and 20,000 of reference was obtained by adding the underflows acre-feet are reasonable estimates of the total for the segments, and the weighted average gradi­ underflow through, and the amount of water mov­ ent of the entire line of reference was used instead ing out, of the subdistrict each year, respectively. of the gradient for each segment. LEAKAGE INTO GREAT SALT LAKE Records of well discharge (table 7) show that The water budget (table 4) for the entire Weber about 3,000 acre-feet per year is pumped from Delta district shows an estimate of 20,000 acre-feet CHEMICAL QUALITY 57 of unidentified discharge, some part of which is feet from the water budget (table 4), it is of the assumed to be direct leakage into Great Salt Lake. same general order of magnitude. This estimate is based on the calculated difference Calculations in the section on evaporation and between volume of water entering the district and evapotranspiration (p. 70) indicate that some 6,000 discharge from all sources evaluated during the acre-feet of water annually might be moving up­ study and is equal to the 20,000 acre-feet of water ward through clay underlying the salt barrens calculated to be moving out of the Weber Delta above the 1952 shoreline of Great Salt Lake. Dur­ subdistrict. Although the equivalence of these ing periods when the lake level is high and the salt estimates is fortuitous, it indicates that they are barrens flooded, this 6,000 acre-feet would be in­ of the correct order of magnitude. It was not pos­ cluded in the total estimate of from 20,000 to sible to measure directly the actual volume of water 70,000 acre-feet per year of ground-water inflow; leaking into the lake by diffuse seepage or through at other times, the 6,000 acre-feet would evaporate undetected sublacustrine orifices. Search during directly from the barrens and contribute nothing the investigation did not succeed in detecting any to the lake. springs of major size. CHEMICAL QUALITY Peck ( 1954) reported that the annual average COMPILATION AND ANALYSIS OF DATA "change of volume (inflow)" of Great Salt Lake The chemical quality of ground and surface wa­ during the period 1910-50 was about 2.6 million ter in the Weber Delta district is known from acre-feet. Much of the change observed can be analyses of more than 500 samples. When the accounted for by variations in streamflow into the present study began in 1953, 67 analyses had been lake. Peck's data show, however, that fluctuations made by the U.S. Geological Survey, the Utah State in precipitation in the drainage areas tributary to Health Department, and others. In addition, sev­ Great Salt Lake have a carryover effect recogniz­ eral partial determinations, principally of chloride, able over a period of about 4 years. The carryover were available for water samples obtained during effect according to Peck, results from discharge the drilling of the Ogden City well at 23d Street from deep artesian aquifers into the lake. The and Van Buren A venue and for samples from a carryover effects (Peck, 1954, fig. 6) are: test well at Utah General Depot. During the period March 1953 to March 1956, the U.S. Bureau Volume change Current year ______No effect. of Reclamation analyzed 426 samples of water fron1 Previous year: the Weber Delta district and the Geological Survey 1st ______Do. analyzed 12 additional samples. Chemical analyses 2d ______0.01 of representative ground and surface waters in the 3d ______.03 district are given in table 9. 4th ______.1 5th ------< .01 A modification of the trilinear-diagram method of analyzing chemical-quality of water data (Piper, Total carryover effect______.14 1944) was used to interpret chemical relationships (pl. 11). Graphs were made to show changes in Using the total figure of 0.14 of volume change, chemical quality of water with distance from an it is calculated that of the total annual average assumed source of recharge and with increasing volume change of 2.6 million acre-feet in the lake, depth. Contour maps were prepared of the content 360,000 acre-feet may be leakage from deeper of specific dissolved constituents, and the results of aquifers. The areas on the southern, eastern, and the entire study of quality of water were sum­ northeastern sides of Great Salt Lake contribute marized on a map (fig. 14) showing areas of different most of the surface water, and probably most of the water types. Individual analyses show clearly the ground-water inflow to the lake; the low arid mingling of waters from adjacent areas of differ­ western side of the lake probably contributes little ent types; therefore, the boundary lines drawn in surface or subsurface water. Because the Weber figure 14 do not represent sharp boundaries. Delta district is about 20 percent of the periphery Results of the chemical analyses are expressed of the lake that is believed to contribute most of the in two ways in this report. Where no chemical underflow, it probably contributes about 20 percent calculations or quantitative comparisons are made, of the total underflow to the lake, or about 70,000 such as in table 9, results are given in parts per acre-feet per year. Although this estimate is million. Where chemical computations have been more than three times the estimate of 20,000 acre- made, or where quantitative comparisons are in- 01 00

TABLE 9.-Chemical analyses of representative samples of ground and surface water in the Weber Delta district [Analyses of U. S. Bur. of Reclamation, unless otherwise noted]

Parts per million u Q)O I

...., ~lC I Q) Na+K dc-:1 Q) J --I I ------ol...., ~ ~ § I ...., 0.~ 't"' Q) ....,Q) I J :>,M 0 QJ o.§ s .3 Q) '"C S< .ge ~ s ;:J Q)el Well No. B ~ ...., "'~ .3~ '"C ~0 +'0 "' '"C~"'rn d'-._ :±:: ·rn~ s d"' "'~ ~~ d ·au ..., or location "'~ §'""' ;:J oO d"' "'~ ·;::~ o~ ..::.@ ::;U 0"' 0. > ;6 0 ~~ "' ~o oO -o ~0 '"Col :.=:ol d "'o ~ 0 ~ '88 §'2 ..au o-~'"~ ~~ Q) ~...:::: Clo ~ ~00 ~~ ..au 'Srn ::::z 000 "'U S:P tzj -§ ...:::: ~

1 1 ~ Great Salt Lake surface 3------~---- ___ 10-13-.54~-- 6,5 407 6,940 86,500 4,070 17' 700 143,000 85 24 268,000 29,800 216 8 51220 165,000 7.4 Weber River 6 1:::1 .49 3718.5 1-1 (B-5-1) 2.5d ______======t _~~~======~~ 12 14 2.0 :::1 ; - 23 18 .1 231 157 14311 [/). 14 14 2.0 34111 28 18 249 -----11 2 ------453 --- 1-3 13 - -~i ------2-17-561 __ ---- 75 20 20 2.7 46 28 7 345 269 3 . 53 ------8 . 3 ~ Ogden River at Ogden ______5-25-56 ______34 1-1 7.2 7.6 1.2 i~~~i~ 11 12 159 115 iZ~~~ 2 .31 2548.4 0 Farmington Creek ~ near Farmington ______7- 9-54 68---- 11 3.7 7.4 1.1 47 2 9.1 5.3 ------68 42 46 2 7 .48 124 8.4 (B-5-1) 25d7 ______D ___ 12- 9-53 __ 9.4 15 2.7 8.0 1.2 52 0 15 7.4 1.7 ----- 77 48 43 2 6 1.0 14718.3 (B-6-1) 23dcb37 ______0 ___ 4-27-43 ______355 11 4 3,000 208 ---- 102 5,080 ------58,650 931 ----- 8 8 ------14 '700 --- (B-7-1) 22abc7 ______N ___ 4- 5-55 1 50---- 33 11 .8 137 0 18 5.3 ---- .07 136 128 112 7 1. 6 263 8. 0 Gateway Tunnel, 4 Sta. 479+30 (A-5-1) 28 ______1-28-54 1 54 11 28 7.3 12 61 1.2 112 2.1 12 14 4.9 .22 142 96 2 0 . 52 26118.3 Gateway Tunnel, 1001 Sta. 608:+-66 (A-5-1) 31______Ill- 8-54,54111 17 3.1 7.6 1.21 57 3.3 13 6.4 1.3 0 91 55 .52 2 ~'!_1_ _ _}5918. 3 1 Subdistricts: D, Weber Delta; K, Kaysville-Farmington; L, Little Mountain; 4 Sodium and potassium calculated as sodium (Na.) N, North Ogden; 0, Ogden-Plain City; W, West Warren. 5 Calculated from determined constituents. 2 Residue on evaporation at 180°C. 6 Average of several samples, prorated in relation to volume of flow. 3 Analysis by U.S. Geological Survey. 7 Spring. CHEMICAL QUALITY 59

R. 2 W R. 1 W R. 1 E·

z

•• 0 / BOX ELDER CO -~r 0::: /- WEBER co ______·_·· w T. 7 N. ~ • •

T. 6 N.

1- _j

T. 5 N.

'\ ~· FORCE BASE • ~ • •• ::0 • • • 'OSyracuse )> • z ·"' ~ • EXPLANATION . '- • • G) T. 4 N. • \ AREAS OF GROUND-WATER .,) • Layton fTl • .. 0 QUALITY • / / •

Calcium or calcium magnesium bicarbonate type More than 50 percent of cations are calcium and magnesium; more than 50 percent of anions are bicarbonate; contains l.ess than 0.8 epm of chloride Sodium bicarbonate type Upper 250 feet is sodium bicarbonate type;

0 lower part is calcium magnesium bicarb

0 ate type. Sodium bica rbo·nate type contains c T. 3 N. Sodium bicarbonate type 250-700 ppm of dissolved solids; calcium magnesium bicarbonate type contains 151J- More than 50 percent of cations are sodium; 300 ppm of dissolved solids more than 50 percent of anions a.re bicar­ bonate, contains less tha.n 0.8 epm of chlor·ide

Calcium magnesium bicarbonate type Sodium chloride type Dissolved solid content of 1,50-700 ppm in upper 150feet and :!00-300 ppm ·in lower part Jtfore than 50 percent of anions arc sodium; Chemical-quality data by more than 50 percent of cations are chloride; D. A. Barker, 1962 usually contains more than 1.5 epm of chloride Boundary between water-quality areas Boundari.es are gradational; dashed boun­ Various types darit·s are gradational over wider a:reas Shows effects of 1m:xing with water of sodium ._ chloride type; usua./ly contains more than • MILES 0.8 eprn of chloride Well Spring

FIGURE 14.-Map showing chemical character of ground water in the Weber Delta district. 60 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT tended, such as in figure 15, results are given as in chemical quality from the subdistrict as a whole equivalents per million. (fig. 14). The shallow aquifer extends only to depths of about 150 feet (p. 37). Waters in the CHEMICAL QUALITY OF GROUND WATER BY SUBDISTRICTS shallow aquifer and in the deeper artesian aquifers Three principal chemical types of ground water are of the calcium magnesium bicarbonate type; were recognized in the Weber Delta district-cal­ but the water in the shallow aquifer contains from cium magnesium bicarbonate, sodium bicarbonate, 450 to 700 ppm of dissolved solids (see well (B-5- and sodium chloride. The calcium magnesium 2)3ddd-1, table 9), whereas the water in the deeper bicarbonate and the sodium chloride types are con­ aquifers contains from 200 to 300 ppm of dissolved sidered to be original types. The sodium bicar­ solids (see well (B-5-2)16ddc-1, table 9). The bonate type presumably results from cation writers conclude that the difference in degree of exchange between the calcium magnesium bicarbon­ mineralization occurs because the recharge area of ate type water and the clays that underlie much of the shallow aquifer is an area of irrigation where the district. The distribution of these main chemi­ the surficial material is fine grained, whereas the cal types of ground water and border areas where recharge area of the deeper aquifers probably is adjacent types apparently intermingle is shown in nearer the mountain front and the surficial material figure 14. Quality of ground water was the major is largely coarse grained and uncultivated. factor in determining the boundaries of the sub­ A few of the shallow wells in the Roy area yield districts of the Weber Delta district (fig. 10), and water that is not suitable for irrigation because in general the subdistricts coincide with areas that of its high sodium eontent. Otherwise, both the yield one chemical type of water. shallow and deep wells in the area yield water that Electric-log data (p. 26) suggest that below is suitable for most uses. 1,300 feet in the Weber Delta subdistrict and below In an area near Syracuse, in the west half of T. 800-1,100 feet in the Kaysville-Farmington subdis­ 4 N., R. 2 W., water in aquifers extending to about trict, water contains so much dissolved solids that 250 feet below the land surface differs in chemical it cannot be used for most purposes. quality from water in deeper aquifers (fig. 14), WEBER DELTA SUBDISTRICT The water from the shallow aquifers in the Syra­ The water in the Weber Delta subdistrict is cuse area is of the sodium bicarbonate type and mostly of the calcium magnesium bicarbonate type, contains from 250 to 700 ppm of dissolved solids but three areas within the subdistrict contain wa­ (see well (B-4-2)16add-4, table 9), whereas water ter of a slightly different quality (fig. 14). Most from the deeper aquifers is of the calcium mag­ of the water has a fairly low concentration of dis­ nesium bicarbonate type and contains from 150 to solved solids, and it is suitable for most uses 300 ppm of dissolved solids (see well (B-4-2) without treatment. Many individuals maintain 20daa-1, table 9). domestic water softeners, however, and in a few Pressure relations in the water-bearing zones localities the iron concentration is high enough to indicate that the shallow and deep aquifers are result in a precipitate which colors the water red. connected (p. 37), and the differences in water In most of the subdistrict, the quality of ground quality apparently result from cation exchange water indicates that it was derived by recharge during upward leakage from the deeper to the from the Weber River and the mountain front. shallower zones in the system. Accompanying this The concentrations of dissolved solids and in­ exchange is an increase in total mineralization. dividual constituents in the ground water are Wells from both aquifers in the Syracuse area similar to the corresponding concentrations deter­ yield water that is suitable for most uses. Many mined from samples taken from the Weber River at shallow wells, however, yield sodium bicarbonate various times of the year and at various stages of type water that is not suitable for irrigation. (See flow. (See wells (B-5-1)27dcc-1 and (B-5-2) well (B-4-2) 16add-4, table 9.) 33ddc and analyses for the Weber River in table A narrow area extending from the mountain 9.) Locally, however, the concentration of dis­ front westward through Layton contains water that solved solids in the ground water exceeds or is less has a slightly lower dissolved-solids content than than that characteristic of water from the Weber does the water in the remainder of the Weber Delta River. subdistrict. The Layton area is not differentiated An area just west of the city of Roy contains in figure 14; but its southern boundary corre­ water in a shallow artesian aquifer that is different sponds to the southern boundary of the Weber CHEMICAL QUALITY 61 Delta subdistrict, and its northern boundary is and earlier lakes. In the quiet water of this bay, approximately parallel with, and 3-4 miles north of, clay was the predominant deposit. the southern boundary. The Pleasant View salient is a mass of rock of In this area, wells yield water which contains Cambrian age (pl. 1) that projects westward from concentrations of dissolved solids and chloride that the Wasatch Range. This spur forms the northern are less than those characteristic of water from boundary of the area of thick clay deposition; the the Weber River (see well (B-4-1)20cbb-1, table southern edge of the area is coincident with the 9). The water is a dilute calcium magnesium Ogden River. The inferred bay could have been bicarbonate type, similar to water from mountain formed when southward-moving lake currents built streams and springs and to water from the Gate­ a bar south from the salient, almost isolating the way Tunnel. It is probable, therefore, that re­ bay from the main lake. The delta and alluvial­ charge from mountain-front sources supplies the fan deposits of the Ogden River probably formed water to the aquifers in the Layton area. the southern edge of the bay. At certain levels of OGDEN-PLAIN CITY SUBDISTRICT the various lakes, the bar may have completely iso­ The ground water in the Ogden-Plain City sub­ lated the bay on the west, and the bay may have district ranges more widely in chemical type than partly or completely evaporated, resulting in the does the ground water in any of the other sub­ deposition of beds of salt. Separate salt beds may districts. Separate strata in a well may yield have been deposited in small subbasins in the bay. water of different chemical composition. For ex­ The bar may have been breached periodically by ample, in well (B-6-1)7cca-1, gravel encountered the Ogden River when the river was flowing over from 195-238 feet yielded a relatively large amount the northern part of its fan. The breaching of the of water containing 2,510 ppm chloride; a zone bar would have rejoined the bay and the main lake, from 450-480 feet yielded a small amount of water and the conditions under which salt beds were containing 360 ppm chloride; and a stratum of deposited would temporarily cease to exist. large quartzite boulders and coarse gravel between Salt may have also been furnished to the bay by 743 and 768 feet yielded water containing 2,540 Utah Hot Springs and El Monte Spring. Utah ppm chloride. Hot Springs apparently has discharged into the Wells of closely equivalent depth within half a basin from near the tip of the Pleasant View mile of one another in the subdistrict commonly salient for a long time. Pillars and algal reefs(?) yield water of different quality. One well will yield of calcareous tufa are exposed east of, and a few water of a quality generally suitable for domestic feet to a few hundreds of feet above, the present use, and another will yield water totally unsuited to spring, suggesting that the spring has deposited domestic, stock, agricultural, or industrial use be­ calcareous material during long time intervals and cause of a high concentration of dissolved solids, at various lake stages (Feth, 1955, p. 60). El principally sodium and chloride. (See wells (B- Monte Spring, in the mouth of Ogden Canyon, may 6-1)8dbd-1 and (B-6-1)8dbb-2, table 9.) also have been tributary to the ancient bay, al­ The reasons for the variations in quality is not though evidence that El Monte Spring existed dur­ clearly understood. A. M. Piper (oral commun., ing Pleistocene time is not so clear as such evidence 1956) suggested that pockets of salty connate at Utah Hot Springs. Masses of gravel cemented water, pans of salt, lenses of heavily salt-impreg­ by calcium carbonate, however, are plastered nated sediments, or all of these may be preserved against the walls of Ogden Canyon as far as three in the alluvial fill. On the basis of Piper's com­ quarters of a mile upstream from the canyon ments it is tentatively suggested that the complex mouth, and they may be erosional remnants of pattern of chemical quality of ground water results Pleistocene spring deposits. At high lake stages, from the unique depositional environment in the the lower part of the canyon may have been choked subdistrict, relative to the rest of the Weber Delta with gravel deposited by the Ogden River, and warm district. Logs of many wells show that a large mineralized waters from the hot springs or their proportion of the subsurface material in the earlier equivalents may have permeated these Ogden-Plain City and North Ogden subdistricts is gravels, in part cementing them. The Ogden River clay (pls. 2, 3). This proportion of clay suggests then removed most of the gravel in the lower that for a long time there was a bay between Ogden canyon, leaving the present isolated outcrops. and the Pleasant View salient that was sheltered In summary, the depositional environment in the from the waves and currents of Lake Bonneville area between Ogden and the Pleasant View salient, 62 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT including much of the Ogden-Plain City and North but the shallow aquifers have not been flushed be­ Ogden subdistricts, was probably varied, but it was cause they are less permeable. generally favorable for the deposition of fine­ grained material and, at times, perhaps local beds WEST WARREN SUBDISTRICT of salt. This variation in the deposits of the area is In the West Warren subdistrict, wells of all probably the cause of the complex pattern of depths yield water of the sodium bicarbonate type occurrence of fresh and salty water. The local salt (fig. 14). Many samples of water had concentra­ beds have been buried by younger sediments and tions of dissolved solids and other constituents now probably form lenses of high salt content in similar to those of water from the Weber River, the general mass of nonsaline or less-saline de­ the inferred source of much of the water in the posits. The saline water in the area is probably subdistrict. For example, the chloride-ion concen­ either connate water of the ancient bay trapped in trations fall within the range of concentrations of the fine-grained material or water that has moved Weber River water sampled at various seasons and through local beds of salt and has become mineral­ at various stages of flow near the mouth of Weber ized by dissolving some of the salt. Therefore, Canyon. (See wells (B-6-3)23bad-1 and (B-6-2) nearby wells of the same depth could readily pene­ 19abd-1 and analyses of water from the Weber trate material of different salt content and yield River, table 9.) For these reasons, and for those water of different chemical composition. cited below in the discussion of chemical-quality changes in the subsurface ( p. 63), it is concluded NORTH OGDEN SUBDISTRICT that the source of recharge for the ground water Some of the least mineralized water in the entire in the West Warren subdistrict is water from the Weber Delta district is found in the North Ogden Weber River and underflow from the Wasatch subdistrict, and the preponderance of wells yield Range. The predominance of sodium in the water water that can be used for most purposes without is due to cation exchange, wherein some of the cal­ treatment. (See fig. 14 and wells in T. 7 N., R. 1 cium and magnesium originally present was ex­ W., table 9.) Recharge to aquifers underlying the changed for sodium. The less mineralized water in subdistrict probably comes from the bedrock of the the subdistrict probably originated as recharge Wasatch Range and by infiltration from streams from the mountain front rather than from the which discharge across the highly permeable zone Weber River. adjacent to the mountains. The deposits under the The ground water in the West Warren subdis­ southwestern part of the North Ogden subdistrict trict is suitable for most uses without treatment. contain a large proportion of clay (pis. 2, 3). This However, the water cannot be readily used for clay also underlies much of the Ogden-Plain City irrigation because prolonged use of sodium bicar­ subdistrict, as discussed in the preceding section. bonate type water on sodium-rich clay soils might Any connate water that was trapped in the clay in prove detrimental, leading in extreme cases to the North Ogden subdistrict evidently has been development of nearly impervious solonetz soils. displaced by fresh water moving southwestward from the mountain front. LITTLE MOUNTAIN SUBDISTRICT The boundary area between the North Ogden Sodium and chloride are the dominant chemical and Ogden-Plain City subdistricts contains water constituents in the ground water of the Little which is of various types but which generally con­ Mountain subdistrict, and the water is so highly tains more than 30 ppm of chloride (fig. 14). There­ mineralized that it is used only for stock (fig. 14; is an indication that water in the deep aquifers is well (B-6-3) 19acc, table 9). Near the base of of the calcium magnesium bicarbonate type, where­ Little Mountain a group of mounds yields a small as water in the shallow aquifers is of the sodium flow of water of the sodium chloride type, and in chloride type. In the southwestern part of the an embayment west of Little Mountain a well about North Ogden subdistrict, well logs show that the 55 feet deep discharges salty water. The associa­ upper 400-500 feet of material is silt and clay with tion of warm saline water with the line of springs a few stringers of intercalated sand. Logs of wells on the salt barrens, together with other information that penetrate below this zone indicate that it is presented in the discussion on geologic structure underlain by a zone of coarse sand and gravel. (p. 22), suggests that the saline ground water in Apparently in the boundary area, fresh water has the Little Mountain subdistrict rises along a major displaced mineralized water in the deep aquifers, fault zone from shattered bedrock at depth. CHEMICAL QUALITY 63 KAYSVILLE-FARMINGTON SUBDISTRICT chemical-quality data from a series of wells at The Kaysville-Farmington subdistrict contains progressively increasing distances from the as­ water of several types (fig. 14). Close to the sumed area of recharge. The horizontal dashed mountain front, the water is of the calcium magne­ lines enclose all plots of chloride content and show sium bicarbonate type, but it contains more chloride that the chloride concentration remains within the than does water from small streams draining the limits of chloride concentration of the inferred Wasatch front in the subdistrict. (See well (B-3- source water, even as far as 21 miles from the 1)2dcc-2 and sample from Farmington Creek, table source, the maximum distance to which wells were 9.) Farther west, the 'Yater is of various types, sampled. The stable chloride content indicates all of which show the effects of mixing with water that there is no appreciable mixing with water of a of the sodium chloride type. It is inferred that sodium chloride type. From about 9-21 miles from small quantities of water with a high chloride the source, the sodium concentration tends to in­ content rise along the Wasatch fault zone, move crease and the calcium content to decrease by equiv­ into the aquifers in this area, and mix with water alent amounts, as indicated by the sloping trend of the calcium magnesium bicarbonate type that lines. The progressive replacement of calcium ions has its source of recharge in the mountain front. by sodium ions, the volumes of clay present in the Scanty data indicate that the aquifers along the area, and the effectiveness of clays as agents in western margin of the subdistrict contain water of promoting cation exchange all suggest that these the sodium bicarbonate type. This implies that changes result from cation exchange. cation exchange takes place within a short distance The average sulfate content of ground water in of the mountain front. The gradient on the piezo­ the Weber Delta district in townships 5-7 decreases metric surface (pl. 9) in the subdistrict is far westward from the area of recharge and the bi­ steeper than gradients throughout most of the carbonate content generally increases in the same Weber Delta district. The steeper gradients direction (table 9). Renick (1924, p. 668-684) has probably reflect the presence of a large proportion shown that organic materials in aquifers reduce of fine-grained material in the valley fill which sulfate and that bicarbonate commonly takes its impedes the movement of water. Sodium in the fine­ place. Zones of clay, silt, and sand rich in organic grained material probably is exchanged for cal­ material are common in the sediments underlying cium and magnesium in the water within a short the Weber Delta district, and probably reactions distance from the source of recharge. similar to those discussed by Renick cause the low Most of the ground water in the subdistrict can sulfate content of some ground-water samples miles be used for most purposes without treatment. In from the recharge area. Fetid-odored pyrite­ general, water near the mountains is low in dis­ bearing clays have been found in well cutttings at solved solids. Farther from the mountains the various depths, further indicating the presence of water is soft and suited for domestic use, but it is organic matter and reducing environments. of sodium bicarbonate type and is generally unsuit­ NATURAL RADIOACTIVITY OF GROUND WATER able for use in irrigation. Some wells in the Farm­ BY A. B. TANNER ington area, especially those 2 miles or more from As is true of ground water in general, the ground the mountains, yield water that is unpleasant to the water of the Weber Delta district contains measur­ taste because of its high chloride content. able amounts of natural radioactivity, some com­ CHEMICAL-QUALITY CHANGES IN THE SUBSURFACE ponents of which were determined by airborne The map of quality-of-water areas (fig. 14) radioactivity surveying, by radiochemical analyses, shows that about 12-15 miles northwest of the and by a study of the distribution of radon in assumed area of recharge near the mouth of Weber water from wells and springs. Canyon, the water type changes from calcium mag­ Anomalous gamma radioactivity of the ground nesium bicarbonate to sodium bicarbonate. This surface in the vicinity of Utah Hot Springs was change is illustrated graphically in figure 15. At observed in the course of a survey conducted with the left end of the graph is a series of plots of airborne scintillation apparatus of the Geological the content of calcium, sodium, and chloride in Survey (J. L. Meuschke, written commun., 1960). water samples taken from the Gateway Tunnel, A radioactive high about 20 times the local back­ from mountain springs, and from the Weber River ground was approximately coextensive with the at several times of the year. Points across the orifices, hardpan deposits, and runoff ditches asso­ graph to the right represent similar plots of ciated with the hot springs, and it was caused by ~

~ ~ t_:l:j t:d 0 7.0 EXPLANATION <~ + "'"' • + ~ Calcium en ~ §60 I 0.0 ·E + 0 ~ a. en Sodium t_:l:j 0: w g a. Q; 0 Cl) > Chloride 0 zf­ ii: ~ w ....J ~ ~ t:;j ::::> 0 p:: w + +I~ z 3.0 • t3 ~ z' 0 0 t-4 f= • 0 ~ 2 .0 1------l f--+-­ .. I U---1* f- + ~ z + w • • • 0 u +r~ '"'%j z + so diurn - .._ - 0 : ~~ ·. u 1.0 - -t ------:;_.~-- --~ __ ..__ ~ • • :It ...... t_:l:j ------• t"' • • Tt +_ ~ L~---~---- t:d ~w 5 6 8 9 10 11 12 13 17 WATER TYPICAL OF 14 15 16 18 19 20 21 t_:l:j RECHARGE AREA DISTANCE FROM THE RECHARGE AREA, IN MILES ~ t:;j t_:l:j FIGURE 15.-Graph showing progressive cation exchange in ground water at increasing distances from the mouth of Weber Canyon. Each trio of points in a vertical ~ line represents the concentrations in a single water sample. Dashed lines indicate range of chloride-ion concentration in water from recharge area. ~ t:;j "'"'w. ;6 c~ t-3 CHEMICAL QUALITY 65 the cumulative deposition of radium-226 and its miles and determined their radon concentrations decay products (radon-222, polonium-218, lead- by the method he described in 1958 (Rogers, 1958). 214, bismuth-214, and others) on the surface over Greater radon concentrations were observed in which the hot-spring water flows. Chemical and water from wells in thick valley fill in the vicinity radiochemical analyses of waters from Utah Hot of known or inferred faults in bedrock than in Springs and Hooper Hot Springs (not included in water taken from wells distant from the surface the airborne survey) are shown in table 10. projections of the fault zones. In order to see whether similar results might be TABLE 10.-Chemical and radiochemical analyses of waters from Utah Hot Springs and Hooper Hot Springs obtained in the Weber Delta district, Rogers and [Analyses by J. D. Hem, U.S. Geol. Survey] H. B. Evans (written commun., 1956) collected water samples from wells in the area southwest 1 Utah Hot Springs, I Hooper Hot Springs, SE>4sec.l4,T.7N.,: SW~,£sec.27,T.5N., and west of the town of North Ogden and deter­ R. 2 W., northern- R. 3. W., eastern­ most orifice of four most orifice of many mined their radon concentration. The only trend Date sample collected ____ _ June 8, 1954 June 20, 1957 observed was an increase toward the southwest, by Temperature CF) ______! 134 130 about one-half, in the average radon concentration Discharge (gpm) ______1 15 1 5 Specific conductance (mi- of water from wells near the southern margin of cromhos per em at 25°C)_ 38,800 14,300 pli ______7.0 7.8 the Pleasant View salient and in the vicinity of projections of fault traces into the area covered Chemical components (ppm): by unconsolidated sediments. Silica (Si02)------­ 38 34 The disposition of wells having water of anomal­ Aluminum (Al) (total)_ .6 .4 Iron (Fe) (total) ______7.6 ously high radon content in proximity to known or Iron in solution when inferred fault zones suggests that the radon is analyzed ______.03 .00 Manganese (Mn) derived from radium-bearing water of the Utah (total)______1.8 1.6 Hot Springs type, rising from the fault zones. Calcium (Ca)______1,180 519 However, consideration of the mechanism leading Magnesium (Mg) _____ ! 36 85 Sodium (Na)______7,610 2,420 to enrichment of the water in radon and considera­ Potassium (K)______1, 040 168 Bicarbonate (IIC03)___ 198 297 tion of the physical characteristics of the sedi­ Carbonate (C03)-- ____ · 0 0 ments and the chemical regime in them suggests Sulfate (S04)- ______198 40 Chloride (Cl)______14,400 4,940 other sources of the radon. The short (3.8 days) Fluoride (F)______2.6 0.9 1 half-life of radon does not permit it to migrate Nitrate (N03)- ______! ______.0 Phosphate ______.0 more than a few tens of feet, even at the rather Radiochemical data: rapid rate of ground-water movement of several Eh ______+.198 volt feet per day; the radium source of radon, there­ Beta-gamma activity fore, must be located in the sediments. (micromicrocuries per liter) ______1,500 <700 The concentrations of radium in the water which Radium (Ra) (micro­ recharges the aquifers in the district are far too microcuries per liter)_ 39 100 Uranium (U) (micro- small to provide the observed concentrations of grams per liter) ______.3 .4 radon. It must be assumed, therefore, that the radium sources are fixed in the sediments, and that a given radon concentration observed in water from 1 Estimated. a well is indicative of radium exposed in the sedi­ The hot-spring waters are of the sodium chloride ments in the subsurface probably only a few feet type and contain concentrations of radium that are from the well bore. The radi urn may be fixed either as much as 100 times the normal concentration, by adsorption on clay or by coprecipitation with less than 1 picocurie per liter, in water from nearby another constituent, such as calcium carbonate or wells in the alluvium. The field relations indicate hydrated ferric oxide, as a result of chemical that the hot-spring waters rise from faults in bed­ reaction. rock. The radium may have been immobilized on clay The distribution of radon in ground water in the in the body of fine-grained material in the valley Bountiful area south of the Weber Delta district fill west and southwest of North Ogden (pis. 2, 3). was studied by A. S. Rogers ( 1955, 1956, and writ­ The northern margin of this body of predominantly ten commun. 1956). He collected about 350 water fine-grained and relatively impermeable material is samples from wells in an area of about 15 square in the same general area as is the zone of anomal- 66 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT ously high radon concentration and inferred or EVAPORATION known faults (pl. 1). Assuming that clay in the A Class A weather station was installed at the fine-grained material did immobilize radium, then Ogden Bay Bird Refuge in cooperation with the the slight anomalously high radon concentration ob­ U.S. Weather Bureau. The weather station con­ served in the ground water could result whether sisted of a 4-foot evaporation pan, a rain gage, an the water was fault derived or water of lower anemometer, and maximum and minimum thermom­ radium content derived elsewhere. eters ; the gages were read daily by Noland Nelson Chemical reactions leading to coprecipitation of of the Bird Refuge. The observed evaporation radium with another constituent may be respon­ rate for the 1955 growing season at the Ogden Bay sible for immobilizing radium in the sediments. In Bird Refuge weather station was similar to the a geologically similar environment in the Bountiful evaporation rate for the same period of time at district in Davis County, the pattern of radon the Bear River Bird Refuge weather station, about concentrations in ground water suggests a relation 20 miles to the north (table 11). The evaporation between radon highs and buried faults (Rogers, rate at the Bear River Bird Refuge for the 1955 1955, 1956). A study (Tanner, 1964) of the chem­ growing season was near the average rate for the ical constituents in the water of some wells near period 1949-55 (table 11). Thus, the evaporation Woods Cross in the same district failed to show a rate at the Ogden Bay Bird Refuge for the 1955 definite relation between subsurface faulting and growing season is assumed to be an approximately the distribution of radon or radium, but it showed average figure for the period 1949-55. This that both calcium carbonate and hydrated ferric figure is further assumed to be the average evapo­ oxides are present in excess concentrations in the ration rate for the entire Weber Delta district. ground water and should be tending to precipitate TABLE 11.-Comparison of evaporation of water from standard in the aquifer. Both constituents tend to immo­ Weather Bureau pans at the Ogden Bay Bird Refuge and the Bear bilize radium and thereby to provide radon sources River Bird Refuge, for the period May-October 1955; and May­ not directly related to faulting. The question of October evaporation from 1949 to 1955 at the Bear River Bird Refuge whether the radon anomalies are linked to subsur­ Evaporation at Ogden Bay B1:rd Refuge Bear River Bird Refuge face faults thus reduces itself to a question of 1955 (inches) (inches) whether the faults add sufficient calcium, carbonate, 11ay ______8.65 7.88 or iron to the aquifers to cause supersaturation, June ______8.17 8.74 July ______10.60 11.27 and whether radium is available for coprecipitation August ______7.60 8.73 when it occurs. The chemical conditions in the September ______5.97 5.94 mixing zones in the aquifers are not well enough October ______4.05 3.33 known at present to fix the cause of coprecipitation in either the Bountiful district or the area near 45.04 45.89 North Ogden. May-October evaporation at Bear River Bird Refuge from 1949 to 1966 Year Inches 1949 ______43.93 EVAPORATION AND EVAPOTRANSPIRATION STUDIES 1950______0) A program was begun in the spring of 1954 to 1951 ______47.31 determine the amount of water discharged in the 1952------(1) 1953 ______46.48 Weber Delta district by evaporation from wetted 1954 ______50.42 surfaces and by transpiration from plants. The 1955 ______45.89 area studied extended from an altitude of 5,000 feet adjacent to the mountains to the 1952 shoreline 1949-55 average ______46.81 of Great Salt Lake (fig. 16). A vegetation survey 1 Record incomplete. of the district was made, evapotranspiration-tank EVAPOTRANSPIRATION studies were made at the Ogden Bay Bird Refuge To determine the amount of water discharged by west of Ogden, and evaporation studies were made transpiration, a vegetation survey was made in on the salt-crust barrens west of the Ogden Bay the Weber Delta district. The land included in the Bird Refuge. No attempt was made to segregate vegetation survey (fig. 16) extends from the east the source of the water discharged by evaporation edge of the cultivated irrigated fields at an altitude and evapotranspiration; thus, the water discussed of 5,000 feet near the foot of the Wasatch Range in this section came from direct precipitation and to the shore of Great Salt Lake on the west, and from surface and underground sources. from T. 3 N. to T. 7 N., inclusive. An area of EVAPORATION AND EVAPOTRANSPIRATION STUDIES 67

R 1 W. R. 1 E.

T. 7 N.

T. 6 N

salt-crust experiments

1952 shoreline of Great Salt Lake

T. 4 N.

Vegetation survey by R. J. Brown, 1956

FI URE 16.-Areas of vegetation and of salt crust from an altitude of 5,000 feet to the 1952 shoreline of Great Salt Lake. 68 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

TABLE 12.-Size of areas in acres, having different evapotranspiration characteristics in the Weber Delta district [The composition of each vegetation group in a given area is discussed in the text)

Location Size, in acres, of numbered areas Total Township Range 2 4 5 6 7 3 N ______1 E______720 180 15 85 ______1,560 2,560 3 N ______1 w______4,180 4,2oo s4o 2,s2o 4,210 s3o 350 16,5oo 3 N ______2 w______340 60 ______s,ooo 30 ______5,430 4 N ______1 w______1o,3oo 750 240 6,8oo 6 1so 1,470 19,7oo 4 N ______2 w______1o,4oo 6,450 1,3oo 290 2,220 160 1,150 22,ooo 4 N ______3 w______1 630 160 ______120 6o ______1,s1o 5 N ______1 w______3,5oo 740 990 9,8oo ______140 2,750 17,900 5 N ______2 w ______l 12,5oo 6,ooo 160 2,100 25 210 1,440 23,ooo s N ______3 w______3,5oo 4,140 2,460 3o 5,320 1,120 ______11,2oo 5 N------4 W------______160 ______160 6 N ______1 w______3,3oo 1,240 430 2,3oo ______so 6,740 14,ooo 6 N ______2 w______13,100 6,180 2,ooo 1,o9o 40 340 3oo 23,ooo 6 N ______3 w______1,1oo 12,ooo 1,s1o 2,490 4,230 s2o 620 28,1oo 6 N ______4 w______90 10 91o 7,460 3 ______8,470 7 N ______1 w______2,8oo 1,010 14o 1,530 ______1s ______s,560 7 N ______2 w______7,6oo 8,130 1,100 2,3oo 2,360 280 ______21,800 7 N ______3 w______420 2,5oo 420 ______18,1oo 1,570 ______23,ooo 7 N ______4 w______9,530 ______9,530

Totals (rounded) ~--7 4, ooo --M,600 --ll,535[--32," 800 --59,"4ool--5,800 --16,400 -2M,ooo about 254,000 acres (table 12) was included in the published data. Table 12 summarizes the results of survey. the study.

A detailed land-classification survey made by AREA 1-CULTIVATED CROPS DEPENDING ON IRRIGATION the Bureau of Reclamation during the 1950-52 Evapotranspiration rates typical of cultivated period was used as an aid in the survey. At each irrigated lands in the Weber Delta district were site where the soil had been sampled, the type of obtained from estimates by Roskelly and Criddle vegetation in the immediate vicinity had been re­ (1952). These rates, plus an additional 51;2 corded. An average of 50 borings was made in inches to account for evaporation during the non­ each 640-acre section, resulting in adequate data growing season, were used to determine evapo­ from which to prepare a map of the distribution transpiration from the area. Table 13 gives the of vegetation. Aerial photographs taken in the fall acreage and the evapotranspiration rate of each of 1952 were also used after the type of vegetation crop. Cultivated irrigated crops grown in the area on the ground was correlated with its appearance have an average annual evapotranspiration rate of on the photographs. Fieldwork was done in areas 170,000 acre-feet. in which the vegetation could not be determined from the land-classification data or from the photo­ TABLE 13.-Annual consumptive use of water by t'arious crops in the graphs. The distribution of the different vegeta­ Weber Delta district tion groups was drawn on a map at a scale of 2,000 [Use during the growing season, after Roskelly and Criddle (1952)) Evapotranspira- feet to the inch and acreages of the groups were tion during the- Annual Annual measured. Crop Area Non- total consump- (acres) Growing growing (inches) tive use As it was impractical to study individual plant season season (acre-feet) (inches) (inches) species when making the vegetation survey, plants ------of similar water requirements were placed in a Ilay ______33,100 28 5.5 33.5 92,000 Corn ______1,630 20 5.5 25.5 3,500 single vegetation group and evapotranspiration for Small grains ______15,700 15 5.5 20.5 27,000 each vegetation group was determined. Then the Peas ______3.260 10 5.5 15.5 4,300 Potatoes ______2,960 18 5.5 23.5 5,800 area of study was divided among seven categories, Sugar beets ______5,480 23 5.5 28.5 13,000 Tomatoes ______4,370 23 5.5 28.5 10,300 five of which were of specific vegetation groups I Other vegetables ____ 2,890 12 5. 5 17.5 4,200 and two of which were unvegetated. Evapotran­ Fruits ______4,150 21 5.5 26.5 9,300 Seeds ______520 15 5.5 20.5 900 spiration rates for crops were taken from published I data, evapotranspiration for two vegetation groups TotaL ______74,o6o ===~=== l70~oo was determined by experiments, evapotranspiration === for the remaining two vegetation groups was AREAS 2 AND 3-SALTGRASS PASTURE AND CATTAILS estimated, and evaporation from the two unvege­ Three experimental tanks were used to determine tated areas was determined by experiment and the consumptive use of water by native vege- EVAPORATION AND EVAPOTRANSPIRATION STUDIES 69 tation in areas 2 and 3. Field conditions were culated evapotranspiration from 54,600 acres of reproduced as nearly as possible by growing salt­ saltgrass pasture is 162,000 acre-feet. grass (Distichlis strictu) and cattails (Typha) in The predominant types of vegetation in area 3 tanks filled with soil and equipped with automatic are cattails, rushes, and reeds, usually growing in devices for supplying measured amounts of water swamps near the edge of Great Salt Lake. Small to the points by subsurface irrigation. The circular areas in which willow and cottonwood trees grow tanks were metal and were 4 feet in diameter and are included in this group as they have a similar 4 feet deep. evapotranspiration rate. Cattails were selected for Mature saltgrass sod was placed in two tanks the tank experiments as studies in other areas and cattails in the third. The tanks containing (Blaney, 1952, p. 63) indicate that the evapotran­ saltgrass were in a saltgrass meadow, and the spiration rate of cattails is near the average for cattail tank was nearby in a slough filled with cat­ this vegetation group. tails. These locations were selected to make con­ The results of the evapotranspiration studies at ditions affecting transpiration as nearly natural as Ogden Bay Bird Refuge for the 1955 growing sea­ possible. The saltgrass and cattails were planted son show that the cattails growing in water 2 inches in the tanks in the spring of 1954, but no records above the surface of the ground had an evapotran­ were kept until 1955 to allow time for the saltgrass spiration rate of 60.42 inches. It was estimated to recover from transplanting and for the cattails that cattails growing under natural conditions to become fully grown. The results for the 1955 would have an evapotranspiration rate of 56 inches growing season are consistent with results of tank for the growing season. The evapotranspiration studies made in other areas (Robinson, 1958, p. for the entire year, including 5.5 inches during the 58). The saltgrass used 33.21 inches of water with nongrowing season, would be about 61.5 inches. the water table 10 inches below the surface and The total discharge of water by evaporation and 32.65 inches of water with the water table 24 inches transpiration for the 11,500 acres of area 3 is below the surface. The cattails used 60.42 inches 59,000 acre-feet. of water. The results of the study are given in AREA 4-DRY -LAND CROPS, GRASSES, AND SHRUBS table 14. Dry-land crops, grasses, and shrubs that depend on precipitation for growth probably use practically TABLE 14.-Consumptive use of 1Dater, in inches, by saltgrass and cattails grown in tanks at the Ogden Bay Bird Refuge during the all the precipitation that falls on areas in which 1955 growing season

----~------·~------they grow. Although the soil can at most times Saltgrass Cattails absorb all moisture as it falls, some precipitation Water used for Water used for Water used for 1955 average depth of average depth of average depth of may be lost by surface runoff. This possible loss 10 inches to 24 inches to water 2 inches water table water table above soil surface by surface runoff is probably balanced by the use May______2.87 1.68 4.24 of a small amount of ground water by the vege­ June ______6. 01 6. 44 1 11 . 81 1 tation. Thus, it is assumed that the precipitation 1 i~:~~t~ ~~~~~==I ~ :i1 ~ :~~ g: ~i is equal to the evapotranspiration. The average September _____ 1 4.96 5.74 9.34 precipitation on area 4 is estimated to be 16.4 inches October______2.68 2.43 3.50 ------annually; thus, the annual discharge by evapotran­ TotaL__ 1 33.21 32.65 60.42 spiration from the 32,800 acres covered by area 4 is 45,000 acre-feet. In area 2, the water table is about 24 inches below AREA 5-NO VEGETATION-SALT-CRUST BARRENS the land surface, and the soil is usually saline. About 60,000 acres (fig. 16) along the shore of The area contains small stands of greasewood and Great Salt Lake was salt-encrusted mudflats, other phreatophytes, but as the most common type completely barren except in scattered small areas of vegetation is saltgrass, consumptive-use data for where upward seepage of relatively fresh ground saltgrass are applied to the entire area. water supported vegetation. Experiments were The evapotranspiration from the tank (table 14) conducted during the growing seasons of 1954 and probably was slightly more than evapotranspira­ 1955 to measure the amount of brine that seeps tion under natural conditions; therefore, it was upward, evaporates, and leaves a salt-crust residue. estimated that the evapotranspiration from salt­ These experiments have been summarized by Feth grass pasture was 30 inches for the growing sea­ and Brown (1962). son. Using this rate and a rate of evaporation of The mudflats west of Ogden Bay Bird Refuge 5.5 inches during the nongrowing season, the cal- were selected as being representative of area 5 70 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT and were used in the salt-crust evaporation age evaporation rate of 49.2 inches at Bear River studies. Five square feet of salt crust was removed Refuge. As the evaporation rates at the Bear from each of three plots, and the plots were visited River Refuge and Ogden Bay Refuge are similar at intervals until a new layer of salt accumulated. (table 11), the evaporation rate of 49.2 inches per The new salt crust was then removed, separated year can be applied to the 5,800 acres covered by from silt, and weighed, thus giving the amount of water in the Weber Delta district. The natural salt deposited by evaporation of brine for a given discharge by evaporation from water surfaces thus period of time. The brine, obtained from a shallow is calculated to be 24,000 acre-feet annually.

well dug near the experimental areas, was analyzed, AREA 7-VEGETATION DIVERSE-SCATTERED MUNICIPAL AND and the amount of brine necessary to produce the INDUSTRIAL AREAS salt crust was calculated. Municipal and industrial areas cover some 16,400 The results of the salt-crust experiments are acres in the Weber Delta district which support summarized in table 15. The calculated average diverse types of vegetation. About one-half the annual rate of upward leakage of 0.1 foot per year annual precipitation that falls on such areas is is little more than a "best guess" because of the assumed to be evaporated or transpired-the re­ wide range in values included in the average. If mainder becomes surface runoff and is accounted the rate of upward leakage in the 60,000 acres of for in calculations of discharge by rivers, drains, salt-crust barrens is assumed to be 0.1 foot per and sloughs. About 11,000 acre-feet of water, year, then about 6,000 acre-feet per year is evapo­ therefore, is evaporated or transpired from area 7. rated from this source in area 5. Perhaps an additional 11,000 acre-feet per year is used for watering lawns and small gardens, for a TABLE 15.-Computation of upward leakage from salt-crust evapora­ tion experiments total of 22,000 acre-feet from area 7.

I Salt accumula- I tion Water evaporated 1 FUTURE DEVELOPMENT (grams) 2 I Annual I Period ------rate of Plot 1 (days) '· I p Grams Cubic feet I leakage The population of the Weber Delta district has er per per (feet) Total square square square grown rapidly in the past 25 years and will prob­ foot foot foot 3 I ------1--[--:------I -- ably continue to increase. The demand for water

A ______'i 13 92.4 I 18.5 199 0.007031' 0.198 A______20 84.9 17. 0 183 . 00646 .118 will likewise increase, possibly beyond the ability B______33 70.3 14.1 152 .00535: .059 of the water resources of the area to meet the B ______22 41.4 8.3 89 .003161 .052 demand. Surface water probably will be developed c------1 55; 73.3 14.7 158 .00562 .037 1 to its economic limit, thus reducing both natural Average ____ ~~~~~~~~~~~~~~~~~~~~-~- recharge to the ground-water body from surface 'Area of each plot was 5 sq. ft. 2 Brine was 93,000 ppm by weight; therefore, each 93 g of salt accumulation flow and the flow of surface water into Great Salt was equivalent to 1,000 g of water. 3 2.832 X 10 4 cc (or g) of water=l cu ft. Lake. In addition to the usable ground water that In addition to the water from upward leakage, has been the principal subject of this report, sur­ about 68,000 acre-feet of water falls as precipita­ face and ground waters of poor quality and indus­ tion on the salt barrens above the 1952 shoreline of trial and sewage waste waters could be developed. Great Salt Lake. Probably about half this water The following section is a discussion in general runs off into Great Salt Lake, and the other half terms of the utilization of water not now used evaporates. The total evaporation from the salt and recommendations for the development of addi­ barrens then consists of 6,000 acre-feet from up­ tional ground water. ward leakage and 34,000 from direct precipitation, UTILIZATION OF SUBSTANDARD WATER or about 40,000 acre-feet. This report has been concerned principally with AREA 6-NO VEGETATION-WATER IN DRAINS, the availability of ground water that is suitable CANALS, AND STREAMS' for most uses, but water that is unsuitable for The evaporation from open surfaces of drains, many uses is also available to be developed in the canals, and streams was computed from existing Weber Delta district. data. The evaporation records at Ogden Bay Bird In many parts of the United States, sewage and Refuge and Bear River Bird Refuge are for the industrial waste waters are purified, either for im­ May to October period only. Correlation with year­ mediate reuse or to prevent pollution of surface long evaporation records at Lehi, Utah, about 55 water. The amount of such waste water that miles south of Ogden, gives a 19-year annual aver- might be reclaimed in the district is not known;

1 Does not include the water of Great Salt Lake. but as all water that is used to carry waste to FUTURE DEVELOPMENT 71 Great Salt Lake is polluted by waste, salvage of seepage out of the area, and by evapotranspiration the carrier water without actually reusing any of from nonbeneficial vegetation. This 90,000 acre­ the waste water itself would represent a sizable feet includes 60,000 acre-feet lost by evapotranspira­ savings. tion from cattails, 20,000 acre-feet of ground-water Much of the sodium chloride type water could be underflow out of the area, and 6,000 acre-feet desalinized (Dodge, 1960). The salt content of of evapotranspiration from the saltgrass pastures, this water is less than that of sea water, and it although saltgrass is not here considered as would, therefore, be less <;ostly to desalinize than is nonbeneficial vegetation. Furthermore, about 9,000 sea water, using some processes. The present cost of the 18,000 acre-feet of water discharged by flow­ of desalination would prohibit its use for irrigation, ing wells in the district is put to little or no bene­ but industry might profitably use such water if ficial use, and might be considered wastage. If other water of suitable quality could not be ob­ water levels were lowered so that most wells tained. stopped flowing, well owners would probably pump Development of saline water might result in only those wells that now discharge water that is benefits additional to that of obtaining more water. beneficially used and, therefore, much of the 9,000 By withdrawing water from aquifers containing acre-feet now wasted could be salvaged. The total salty water, pressure in those aquifers would be amount of water that could be salvaged is not reduced and there would be less tendency for known, however, it might be as much as one-fourth saline water to move into and contaminate aquifers of the amount being wasted. that presently produce water of good quality. Recharge experiments made during this investi­ This would be an important benefit because future gation indicate that the gravel near the mouth of large-scale development of fresh ground water in Weber Canyon is highly receptive to induced re­ the district might cause saline water to migrate charge and is directly connected with the artesian toward the areas of fresh water. aquifers. Additional experiments are needed to A transitional stage in ground-water develop­ determine the most feasible and economic means of ment possibly may occur during which it will be inducing recharge during periods when the river desirable to pump water from saline-water aqui­ contains water in excess of water rights and to fers, such as in Tps. 6 and 7 N., in order to reduce determine whether desilting works will be needed pressures and thereby protect fresh-water aquifers in permanent recharge operations. Public owner­ in adjacent areas from contamination. During ship of the flood plain near the mouth of Weber such a transitional period, the saline water pumped Canyon would insure that this area would always may have to be wasted to Great Salt Lake until be available to be used for artificial recharge. the demand for water becomes sufficiently great to As the drilling of new wells proceeds in the make desalinization economically feasible. district and discharge increases, records of water

DEVELOPMENT OF GROUND WATER levels and volumes of water discharged by wells Several steps should be taken in order to develop should be maintained, and the significance of these efficiently the ground-water resources of the Weber data should be evaluated periodically. The report Delta district. Withdrawal of ground water on ground-water conditions in the East Shore area should be increased to lower the artesian pressure by Smith and Gates ( 1963) is the first such evalua­ and reduce wastage; continuing studies should be tion that has been made. Quantitative records of made of changes in water levels and artesian discharge can be compared to changes in water pressures, changes in discharge, and changes in levels to determine whether or not the ground­ chemical quality; and recharge experiments should water reservoir is being developed efficiently. Over be continued in order to determine the ·feasibility long periods of time, comparing water levels with of large-scale induced recharge. Eventually, the precipitation will permit the differentiation of cli­ ground-water body should be operated as a reser­ matic effects from the effects caused by man's use voir, where excess water during wet periods is of water. Determining the effect of each will help stored to be used during periods of drought. in managing the reservoir. Additional development of ground water in the Studies of chemical quality of water should be Weber Delta district would reduce wastage by continued in the Weber Delta district. The present seepage and use by nonbeneficial vegetation. A study has established the broad patterns of occur­ total of about 90,000 acre-feet in the district is lost rence of water of various chemical types, has aided each year by evaporation from the saltflats, by in determining areas of recharge and directions of 72 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT movement, and has yielded some information re­ requires a fluctuation of the water level. Maintain­ garding chemical-quality boundaries. The district, ing at all times a static water level-or pressure however, is large, the water-quality relations are head-inevitably means that operation of the reser­ complex, and the water quality in strata more than voir is wasteful and inefficient, because an unchang­ 1,300 feet below the land surface is not fully known. ing water level or piezometric surface requires Water samples from all new wells should be that the subsurface reservoir be filled at all times obtained and analysed. This information should to the same level. In analogy, it is as though a be examined periodically to determine whether the surface reservoir were kept at all times filled to current conclusions regarding the location and na­ spillway level and that at all times water was being ture of water-quality boundaries need modification allowed to waste over the spillway. The "spillway and to confirm or change other conclusions drawn waste water" from the subsurface reservoir of the from chemical-quality data. Weber Delta district is that water which is dis­ Selected wells near boundaries between different charged to the atmosphere through consumptive chemical types of water should be sampled period­ use by nonbeneficial vegetation, and that which is ically to determine any migration of waters of one evaporated from saturated land surfaces or from chemical type toward areas containing water of a Great Salt Lake after upward leakage from the different type. The effect of heavy development in aquifers. This wastage is about 100,000 acre-feet any area must be observed, and such areas pro­ annually, and by proper management of the reser­ tected against migration of water of undesirable voir it could be reduced appreciably. quality, if need for such protection should be dis­ covered. Smith and Gates (1963) evaluated the REFERENCES chemical-quality data collected through 1961, and Antevs, Ernst, 1952, Geochronology of the Deglacial and Neothermal ages [abs.]: Geol. Soc. America Bull., v. concluded (p. 39) that no relation between ground­ 63, no. 12, pt. 2, p. 1320. water development and changes in chemical quality Bell, G. L., 1952, Geology of the northern Farmington Moun­ was yet evident. tains, in Marshall, R. E., ed., Geology of the Central Finally, as the demand for ground water in­ Wasatch Mountains, Utah: Utah Geol. Soc. Guidebook creases, the quality of water in the deeper strata to the geology of Utah No. 8, p. 38-51. should be more completely determined. Such a Bissell, H. J., 1952, Stratigraphy of Lake Bonneville and as­ sociated Quaternary deposits in Utah Valley, Utah determination will help clarify present thinking [abs.]: Geol. Soc. America Bull., v. 63, no. 12, pt. 2, about upward leakage from aquifer to aquifer; p. 1358. about the relative amount of lateral movement and -- 1963, Lake Bonneville: Geology of southern Utah of upward movement of ground water in the west­ Valley, Utah: U.S. Geol. Survey Prof. Paper 257-B, ern part of the area; and, in general, about the p. 101-130. volume of ground water that is available for sus­ Blackwelder, Eliot, 1910, New light on the geology of the Wasatch Mountains, Utah: Geol. Soc. America Bull., v. tained use in the area. 21, p. 517-542, 747. Efficient, orderly development of the ground­ -- 1939, Pleistocene mammoths in Utah and vicinity: water resources in any area requires that it be Am. Jour. Sci., v. 237, no. 12, p. 890-894. clearly recognized that the aquifers constitute a --1948, The geological background, in The Great Basin: reservoir analogous in most respects to a surface Univ. Utah Biol. Ser., v. 10, no. '7, p. 1-16. reservoir. As more accurate data on the amount Blaney, H. F., 1952, Determining evapotranspiration by phreatophytes from climatological data: Am. Geophys. of recharge and discharge in the district become Union Trans., v. 33, no. 1, p. 61-66. available, the operation of the reservoir can be Bronshtein, Zinovii S., 1947, Crustaceans. Fresh-water Os­ planned. Over a long period of time, the amount tracoda, Moskva-Leningrad, Izd-vo Acad. Nauk SSSR, of ground water in storage, as measured by water in Fauna SSSR, Crustacea, v. 2, no. 1, (new ser., no. levels in key observation wells, may be reduced in 31) 341 p. Brown, Merle, 1960, Climate of Utah: U.S. Dept. Commerce, times of need, such as dry years, and increased Weather Bur., Climatography of the United States, no. during exceptionally wet years. 60-42, 15 p. Operation of a surface reservoir involves with­ Brown, R. H., 1953, Selected procedures for analyzing aqui­ drawal of water for use in times of demand with a fer test data: Am. Water Works Assoc. Jour., v. 45, resultant lowering of the water level in the reser­ p. 848-866. voir. During periods of lesser demand, the water Connor, J. G., Mitchell, C. G., and others, 1958, A compila­ tion of chemical quality data for ground and surface level in the surface reservoir is permitted to rise. waters in Utah: Utah State Engineer Tech. Pub. 10, In like manner, operation of a subsurface reservoir 276 p. REFERENCES 73

Dennis, P. E., 1952, Ground-water recharge in the East Jennings, J. D., 1953, Danger Cave: A progress summary: Shore area, Utah: U.S. Geol. Survey open-file report, El Palacio, v. 60, p. 179-213. 17 p. Jones, D. J., and Marsell, R. E. 1952, Pleistocene lake sedi­ Dennis, P. E., and McDonald, H. R., 1944, Ground water in ments in the vicinity of Salt Lake City, Utah [abs.]: the vicinity of Ogden, Utah: U.S. Geol. Survey open-file Geol. Soc. America Bull., v. 63, no. 12, pt. 2, p. 1364. report, 106 p. --- 1955, Pleistocene sediments of lower Jordan Valley, Dodge, B. F., 1960, Fresh water from saline waters-an en­ Utah: Utah Geol. Soc. Guidebook to the geology of Utah gineering research problem: Am. Scientist, v. 48, no. 4, no. 10, p. 85-112. p. 476-513. Jones, P. H., Turcan, A. N., Jr., and Skibitzke, H. E., 1954, Eardley, A. J., 1938, Sediments of Great Salt Lake, Utah: Geology and ground-water resources of southwestern Am. Assoc. Petroleum Geologists Bull., v. 22, p. 1305- Louisiana: Louisiana Geol. Survey Bull. 30, 285 p. 1411. LeConte, Joseph, 1890, Elements of geology: 2d ed., New --- 1944, Geology of the north-central Wasatch Moun­ York, D. Appleton & Co., 588 p. tains, Utah: Geol. Soc. America Bull., v. 55, p. 819-894. Leggette R. M., and Taylor, G. H., 1937, Geology and Eardley, A. J., ed., 1955, Tertiary and Quaternary geology ground-water resources of Ogden Valley, Utah: U.S. of the Eastern Bonneville Basin: Utah Geol. Soc. Guide­ Geol. Survey Water-Supply Paper 796-D, p. 99-161. book to the geology of Utah no. 10, 132 p. Logan, J. A., 1951, Origin of boron in the ground waters of Eardley, A. J., and Hatch, R. A., 1940, Proterozoic ( ?) rocks California [abs.]: Geol. Soc. America Bull., v. 62, no. in Utah: Geol. Soc. America Bull., v. 51, p. 795-843. 12, pt. 2, p. 1505. Eardley, A. J., and Gvosdetsky, Vasyl, 1960, Analysis of McDonald, H. R., and Wantland, Dart, 1960, Geophysical Pleistocene core from Great Salt Lake, Utah: Geol. Soc. procedures in ground water study: Jour. Irrigation and America Bull., v. 71, p. 1323-1344. Drainage Div., Am. Soc. Civil Engineers, Sept. 1960, Emiliani, Cesare, 1955, Pleistocene temperatures: Jour. Ge­ p. 13-26. ology, v. 63, p. 538-578. Meinzer, 0. E., 1923a, The occurrence of ground water in the Feth, J. H., 1954, Preliminary report of investigations of United States with a discussion of principles: U.S. Geol. springs in the Mogollon Rim region, Arizona: U.S. Survey Water-Supply Paper 489, 321 p. Geol. Survey open-file report. --- 1923b, Outline of ground-water hydrology with defi­ --- 1955, Sedimentary features in the Lake Bonneville nitions: U.S. Geol. Survey Water-Supply Paper 494, Group in the East Shore Area near Ogden, Utah: Utah 71 p. Geol. Soc. Guidebook no. 10, p. 45-69. Morrison, R. B., 1952a, Late Quaternary climatic history of Feth, J. H., and Brown, R. J., 1962, Method for measuring the northern Great Basin [abs.]: Geol. Soc. America upward leakage from artesian aquifers using rate of Bull., v. 63, no. 12, pt. 2, p. 1367. salt-crust accumulation: U.S. Geol. Survey Prof. Paper --- 1952b, Stratigraphy of Lake Lahontan and associated 450-B, p. BlOO-BlOl. Quaternary deposits in the Carson Desert area, near Fix, P. F., and others, 1950, Ground water in the Escalante Fallon, Nevada [abs.]: Geol. Soc. America Bull., v. 63, Valley, Beaver, Iron, and Washington Counties, Utah: no. 12, pt. 2, p. 1367-1368. Utah State Engineer 27th Bienn. Rept., p. 109-210. Moulder, E. A., Torrey, A. E., and Koopman, F. C., 1953, Frye, J. C., and Leonard, A. B., 1952, Pleistocene geology Ground-water factors affecting the drainage of Area of Kansas: Kansas Geol. Survey Bull. 99, 230 p. IV, First Division, Buffalo Rapids irrigation project, Gilbert, G. K., 1890, Lake Bonneville: U.S. Geol. Survey Montana: U.S. Geol. Survey Circ. 198, 46 p. Mon. 1, 438 p. Nolan, T. B., 1928, Potash brines of the Great Salt Lake --- Studies of Basin-Range structure: U.S. Geol. Survey Desert, Utah: U.S. Geol. Survey Bull. 795, p. 25-44. Prof. Paper 153, 92 p. --- 1943, The Basin and Range province in Utah, Ne­ Gvosdetsky, Vasyl, and Hawkes, H. B., 1953, Reappraisal of vada, and California: U.S. Geol. Survey Prof. Paper the history of Lake Bonneville: Utah Univ. Bull., v. 43, 197-D, p. 141-196. 70 p. Peck, E. L., 1954, Hydrometeorology of Great Salt Lake: Halpenny L. C., and others, 1952, Ground water in the Gila Univ. Utah, Engineering Expt. Sta. Bull. 63, 57 p. River Basin and adjacent areas, Arizona: A summary Peterson, William, 1946, Ground water supply in Cache U.S. Geol. Survey open-file report. Valley, Utah: Utah Agricultural Ext. Service Bull., Hunt, C. B., and Sokoloff, V. P., 1950, Pre-Wisconsin soil in new ser. 133, 101 p. the Rocky Mountain region, a progress report: U.S. J>iper, A. M., 1944, A graphic procedure in the geochemical Geol. Survey Prof. Paper 221-G, p. 109-123. interpretation of water analyses: Am. Geophys. Union Hunt, C. B., Varnes, H. D., and Thomas, H. E., 1953, Lake Trans., pt. 6, p. 914-923. Bonneville: Geology of northern Utah Valley, Utah: Piper, A. M., and others, 1939, Geology and ground-water U.S. Geol. Survey Prof. Paper 257-A, 99 p. hydrology of the Mokelumne area, California: U.S. Ives, R. L., 1946, Bottle springs: Jour. Geology, v. 54, no. 2, Geol. Survey Water-Supply Paper 780, 230 p. p. 123-125. Poland, J. F., Piper, A. M., and others, 1956, Ground-water Jacob, C. E., and Lohman, S. W., 1952, Non-steady flow to a geology of the coastal zone, Long Beach, Santa Ana well of constant drawdown in an extensive aquifer: Am. area, California: U.S. Geol. Survey Water-Supply Pa­ Geophys. Union Trans., v. 3, p. 559-569. per 1109, 162 p. 74 LAKE BONNEVILLE: GEOLOGY AND HYDROLOGY OF THE WEBER DELTA DISTRICT

Renick, C. B., 1924, Some geochemical relations of ground Tanner, Allan B., 1964, Physical and chemical controls on water and associated natural gas in Lance formation, distribution of radium-226 and radon-222 in ground wa­ Montana: Jour. Geology, v. 8, p. 668-684. ter near Great Salt Lake, Utah, chap. 14, in Adams, --- 1925, Base exchange in ground water by silicates as John A. S., and Lowder, Wayne M., eds. The natural illustrated in Montana: U.S. Geol. Survey Water­ radiation environment: Chicago, Ill., Chicago Univ. Supply Paper 520-D, p. 53-72. Press, p. 253-276. Richmond, G. M., Morrison, R. B., and Bissell, H. J., 1952, Taylor, G. H., and Leggette, R. M., 1949, Ground water in Correlation of the late Quaternary deposits of the La the Jordan Valley, Utah: U.S. Geol. Survey Water­ Sal Mountains Utah, and of Lakes Bonneville and Lahon­ Supply Paper 1029, 356 p. tan by means of interstadial soils [abs.]: Geol. Soc. Theis, C. V., 1935, The relation between the lowering of the America Bull., v. 63, no. 12, pt. 2, p. 1369. piezometric surface and the rate and duration of dis­ Robinson, T. W., 1958, Phreatophytes: U.S. Geol. Survey charge of a well using ground-water storage: Am. Geo­ Water-Supply Paper 1423, 84 p. phys. Union Trans., v. 16, p. 519-524. Rogers, A. S., 1955, Geological significance of radon in stream and well waters [abs.] : Geol. Soc. America --- 1938, The significance and nature of the cone of de­ Bull., v. 66, no. 12, pt. 2, p. 1609. pression in ground-water bodies: Econ. Geology, v. 38, --- 1956, Applications of radon concentrations to ground­ p. 889-902. water studies near Salt Lake City and Ogden, Utah Thomas, H. E., 1946, Ground water in Tooele Valley, Tooele [abs.]: Geol. Soc. America Bull., v. 67, no. 12, pt. 2, County, Utah: Utah State Engineer 25th Bienn. Rept., p. 1781-1782. p. 91-238. --- 1958, Physical behavior and geologic control of ra­ Thomas, H. E., and Nelson, W. B., 1948, Ground water in don in mountain streams: U.S. Geol. Survey Bull. the East Shore area, Utah; part 1, Bountiful district, 1052-E, p. 187-211. Davis County: Utah State Engineer 26th Bienn. Rept., Roskelley, C. 0., and Criddle, W. D., 1952, Consumptive p. 52-206. use and irrigation water requirements of crops in irri­ Thomasson, H. G., Olmsted, F. H., and LeRoux, E. F., 1960, gated areas of Utah: Utah State Engineer 28th Bienn. Geology, water resources, and usable ground-water stor­ Rept., p. 85-110. age capacity of part of Solano County, California: U.S. Rubin, Meyer, and Alexander, Corinne, 1958, U.S. Geological Geol. Survey Water-Supply Paper 1464, 693 p. Survey radiocarbon dates [Pt.] 4: Science, v. 127, p. Wenzel, L. K., 1942, Methods for determining permeability 1476-1487. of water-bearing materials: U.S. Geol. Survey Water­ Russell, I. C., 1885, Geological history of Lake Lahontan, a Supply Paper 887, 192 p. Quaternary lake of northwestern Nevada: U.S. Geol. Williams, J. S., 1952, Red Rock Pass, outlet of Lake Bonne­ Survey Mon. 11, 288 p. ville [abs.]: Geol. Soc. America Bull., v. 63, no. 12, pt. 2, Smith, R. E., 1961, Records and water-level measurements p. 1375. of selected wells, and chemical analyses of ground wa­ --- 1962, Lake Bonneville: Geology of Southern Cache ter, East Shore area, Davis, Weber, and Box Elder Counties, Utah: U.S. Geol. Survey open-file report ( du­ Valley, Utah: U.S. Geol. Survey Prof. Paper 257-C, plicated as Basic-Data Report 1), 35 p. p. 131-152. Smith, R. E., and Gates, J. S., 1963, Ground-water condi­ Winslow, A. G., Doyel, W. W., and Wood, L. A., 1957, Salt tions in the southern and central parts of the East water and its relation to fresh ground water in Harris Shore area, Utah, 1953-61: Utah Geol. and Mineralog. County, Texas: U.S. Geol. Survey Water-Supply Paper, Survey Water-Resources Bull. 2, 41 p. 1360-F, p. 375-407. INDEX

[Italic page numbers indicate major references)

Page Page Page A E

Acknowledgments______6 Eardley, A. J., cited ______21 Ground-water basin, boundaries ______10, 11 Active storage, defined ______46 East Shore area______15 defined______12 Alluvial fan, pre-Alpine ______25 definition______5 Ground-water discharge______13 Alpine Formation ______l4, 15, 16, 22, 30, 39 Economic geography ______Ground-water leakage into Great Salt Lake ___ 56 measured sections ______17, 18 El Monte Spring ______50, 61 Ground-water reservoir ______1C sand and graveL ______18 faulting ______52 volumes of water______45 Alpine lake______14 Electric logs for oil tests______30 Aquifer tests, hydraulic characteristics ______52 Evans, H. B., quoted ______65 H Evaporation ______20, 57 Aquifers: Hardpan deposits______lS concentrations of radium in water which Area 5-No vegetation--salt-crust Hickey oil-test 2 ______1r recharges ______65 barrens______69 Hill Air Force Base ______25, 4r Delta artesian______48 Area 6-N o vegetation-water in drains, wells ______36, 37 major artesian ______35 canals, and streams ______70 Hinckley Field wells ______3'i permeability ______54 Area 7-Vegetation diverse--scattered Hooper Hot Springs ______5(1 shallow ______37 municipal and industrial areas ___ 70 Sunset artesian______48 chemical and radiochemical analyses Evaporation studies______66 of water______65 transmissibility ______54 Evapotranspiration ______34, 38, 42, 50, 69 Hooper Pilot Drain ______25 Area !-Cultivated crops depending Horst of Precambrian rock ______28 B on irrigation ______68 Hough, M. J. fossils identified by ______32 Areas 2 and 3-Saltgrass pasture and Hunt, C. B., cited ______l3, 14,32 Bear River Bird Refuge, evaporation cattails ______68 studies ______66, 70 Benchlands______19 Area 4-Dry-land crops, grasses, and shrubs______69 Bonneville Basin ______7, 14, 23,39 Evapotranspiration studies ______66 Intermediate stage of Lake Bonneville______14 Bonneville Formation, sand and gravel Introduction______3 deposits ______19 F Irrigated areas and canals, seepage______43 Bonneville stage of Lake Bonneville______14 Farmington area wells ______63 Irrigation______13 Bountiful area, distribution of radon in Farmington Canyon Complex ______12 recharge______43 gound water ______65 Fault, east flank of Little Mountain ______22 Bountiful district______50 major______20 J Brown, R. W., plant fragments examined by __ 32 minor______2 2 Flood-plain deposits of Recent age ______19 Jess Hickey Oil Co. Rushforth !______21 c Wilcox L ______2} Fluctuations in artesian pressure, long-term ______49 Cambrian limestone ______12 K Canals, recharge______43 Folds ______20 Candona ______31, 32 Fossils, Alpine Formation ______19 Kaysville-Farmington, ground-water invertebrate ______31 Chemical and radiochemical analyses of subdistrict______3 $J mollusks ______32 waters, from Hooper Hot Kaysville-Farmington area, water recoverable_ 49 Springs______65 ostracodes ______16, 17, 19, 26, 31, 32 Kaysville-Farmington subdistrict, aquifers ____ 5'l plant ______32 from Utah Hot Springs ______65 chemical quality of ground water ______61 Provo Formation ______17 Chemical-quality changes in the subsurface ___ 63 vertebrate ______32 Chemical quality of ground water, L by subdistricts ______60 Future development______----- ____ 70 Lake Bonneville, chronology ______13 Chemical quality of water, compilation and G shorelines______7 analysis of data ______57 Lake Bonneville deposits ______from wells ______37 Gateway TunneL------42, 63 Geology ______10 Lake Bonneville Group ______16, 22, 3') Clay deposited by Great Salt Lake ______20 Geophysical data, interpretation ______28 mapping______11 Clearfield wells ______36, 37 Gilbert, G. K., cited ______7, 14 Climate ______9, 23 problems in separating and identifying Glaciation, Pleistocene Epoch ______23 formations of______14 Coefficient of storage of an aquifer, defined ____ 52 Goode, H. D., cited ______23 Lakes ______30 Coefficient of transmissibility, defined ______52 Gravel, Recent______20 Land-classification survey------______20, 68 Criddle, W. D., cited ______68 Layton area wells______60 Cyprideis______32 Gravel lenses______23 Gravel pit______39 Lehi, Utah______70 Cytherissa lacustris ______16, 17, 31, 32 Gravel zones, sources of water______23, 26 Lewis, G. E., fossils identified by ______32 Gravity survey______2 6 Limnocythere ______31, 32 D Great Salt Lake, clay deposited by ______20 Little Mountain ______7, 11, 12, 22, 26, 28 Definition of project area ______5 ground-water leakage ______56 consolidated rocks ______12 Delta aquifer ______25, 26, 36, 48, 49, 56 shoreline ______7, 11, 57 fault on east flank ______22 Discharge______49 Ground water______3 5 ground-water subdistrict______38, 4.9 by evapotranspiration and seepage ______66 confined, causes of loss ______35 Little Mountain subdistrict, chemical by springs ______50 development of______71 quality of ground water ______62 from wells ______-49, 56 natural radioactivity oL ______63 Location of project area______5 Drainage ______34 recharge ______19, 38, 65 Loess______23 Drillers' logs ______23 subdistricts and their aquifers______3 6 Logs of test wells ______25, 61, 6'2 75 76 INDEX

Page Page Page M u Mabey, D. R., cited ______22, 26 Profiles, seismic ______30 Uintah Bench ______17, 18, 19, 20, 22 Maps, lithofacies______25 Promontory Point ______22 Unconsolidated deposits, Pleistocene and Marl beds ______22, 32 Provo Formation ______14, 15, 16, 19, 31 Recent age______12 Measured section, Alpine Formation ______17, 18 measured sections ______17, 18 Unconsolidated rock, thickness ______• ___ 10 Provo Formation ______17, 18 Provo stage of Lake Bonneville ______14, 19 volume of______.28 Meinzer, 0. E., cited ______45 Purpose of study______3 U. S. Bureau Reclamation, Weber Basin Methods of investigation______3 Project described ______I II Methods of study ______11 Q U. S. Bureau Reclamation test wells: Methods used in estimating active storage in well 1______25, 26 artesian aquifers ______46 Quaternary deposits______13 well 2 ______2 5, 2 6 Morrison, J.P. E., fossils identified by ______32 well 3A ______25, 26 Mountain-front streams, runoff ______41 R well 4A ______22, 25, 31, 32 Mountain-front subsurface recharge ______41 well 5A ______25, 26 Movement of ground water ______54 Radioactive age determinations ______32 well 5B ______22, 26, 28, 30, 45 Mudflow deposits ______13 Radioactivity, Utah Hot Springs ______63 Utah Hot Springs ______50, 61 Radium, fixation in sediments______65 chemical and radiochemical Recent deposits ______19 N analyses from ______65 Recent gravel______20 faulting ______52 Natural radioactivity of ground water______63 Recharge, from surface streams______3 9 radioactivity______63 Naval Supply Depot______25 subsurface from mountain front______41 Nelson, W. B., quoted______5 summary of______39 w North Ogden, ground-water subdistrict __ 38, 54, 61 Recharge experiments, artificiaL______44 Wantland, Dart, quoted ______28 North Ogden area, water recoverable______49 near mouth of Weber Canyon ______44 Warm Springs fault______50 North Ogden subdistrict, aquifers______53 Relief, along Wasatch fault ______21 Wasatch fault______21, 22,26 chemical quality of ground water______62 River channels, deposition of material ______25 Rocks of pre-Quaternary age ______12 Wasatch fault zone ______6, 22, 39, 66 Rogers, A. A., quoted ______65 Wasatch front______----______6 0 Roscoe, E. J., fossils examined by ______32 Wasatch Range ___ 12, 13, 21, 23, 28, 34, 35, 42, 66 Ogden Bay Bird Refuge ______34 Roskelley, C. 0., cited ______68 consolidated rock ______12, 15 evaporation studies ______66, 70 Roy area wells ______37, 60 Wastage of water______72 evapotranspiration studies ______69 Rubin, Meyer, radioactive age determinations_ 32 Water, utilization of substandard______70 Ogden-Brigham canaL ______3 4 Runoff, mountain-front streams______41 volume ______54 Ogden Canyon ______61 Water-bearing properties of the rocks ______12 Ogden City wells ______33, 34 s Water budget______33 Ogden-Plain City, ground-water Water entering the area ______33 subdistrict______37, 45, 49, 54, 61 Salt beds, deposition ______61 Water leaving the area ______34 Ogden-Plain City subdistrict, aquifers ______53 Salt Lake City Airport, precipitation Water recoverable, by partial dewatering of chemical quality of ground water ______61 and temperatures______9 the artesian aquifers, Weber Ogden River ______33, 34, 54, 61 Salt Lake Formation ______13 Delta subdistrict______47 annual recharge ______41 occurrence in subsurface of the basin_ _ _ _ _ 30 from other areas______49 Water resources ______33 Ogden Sugar Factory, precipitation and Sand, black______25 temperatures______9 Schultz, C. B., fossils identified by ______32 Weber Aqueduct ______41 Weber Canyon ______71 Ogden-West Ogden area, water recoverable ___ 49 Scope of study______3 Olson, Richard, quoted ______22 Seepage, from irrigated areas and canals______43 Weber Canyon radon studies ______42 Seepage losses, measurements ______39 Weber Delta, ground-water subdistrict_ ____ 36, 54 p Seismic survey, shallow-reflection______28 Weber Delta district, plain, description______7 Shore features ______15, 19 Weber Delta subdistrict, active storage ______46 Paleontology______31 Sloughs, flow in major ______34 changes in storage______45 See also Fossils. Sohn, I. G., cited ______26, 31, 32 chemical quality of ground water______60 Paleozoic rocks______12 Specific yield, defined ______52 water recoverable by partial Peck, E. L., quoted ______57 Springs, discharge by ______50 dewatering of the artesian Peg modeL ______23 mineral content______50 aquifers ______47 Permiability, verticaL ______43 Stansbury stage of Lake Bonneville______16 Weber River ______33, 34, 36, 37, 60, 61 Physical geography______6 Storage______45 flood plain ______44 Piezometric surface ______41, 54 Stratigraphy of the rocks ______12 source of recharge ______39 gradient______63 Structure______20 Well interference ______53 Piper, A.M., cited ______57, 61 Subsurface, formation boundaries ______30 Well-numbering system used in Utah______9 Plain City ______34 Subsurface geologic studies______22 Wells ______25, 61,62 Pleasant View salient______7, 11, 12, 13, 22, 61, 65 Sunset aquifer ______25, 37, 56 Clearfield ______36, 37 consolidated rocks ______12 Sunset artesian aquifer ______48 discharge from______49 Pleistocene formations in subsurface of Sunset wells______36 Farmington area______63 the basin ______30 Surface geology ______12 Hill Air Force Base ______36, 37 Pleistocene(?) strata, occurrence in Surface water ______33 Hinckley Field ______37 subsurface of the basin ______30 Syracuse area wells ______37, 60 Layton area______60 Porosity of sedimentary rocks ______45 observation______44 Precambrian rocks ______12 Ogden City ______33, 34 T horst______28 pumped ______36 Precipitation ______9, 34 Tanner, L. G., fossils identified by ______32 Roy ______37 recharge______43 Taylor, D. W., fossils identified by ______32 Roy area ______60 source of recharge ______38 Temperature ______Sunset______36 volume over Wasatch Range ______41 springs ______50 Syracuse______3 7 Previous investigations______5 Test wells ______22, 23, 25, 28, 31, 44, 55, 60 Syracuse area ______60 Principal recharge area______3 8 logs of______25, 61, 62 West Warren, ground-water subdistrict_ ____ 38, 49 Problems in separating and identifying Thomas, H. E., quoted ______5 West Warren subdistrict, chemical quality of formations of Lake Bonneville Tintic quartzite ______13 ground water ______62 Group _____ ---_-- ______14 Topography ______6, 14, 16, 21, 22, 32, 35, 50 Willard Bay ______13

*U.S. GOVERNMENT PRINTING OFFICE: 1966-0 214-670